/*    $OpenBSD: ieee80211_node.c,v 1.198 2023/10/22 12:01:36 stsp Exp $    */
/*    $NetBSD: ieee80211_node.c,v 1.14 2004/05/09 09:18:47 dyoung Exp $    */

/*-
 * Copyright (c) 2001 Atsushi Onoe
 * Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
 * Copyright (c) 2008 Damien Bergamini
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "bridge.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/endian.h>
#include <sys/errno.h>
#include <sys/sysctl.h>
#include <sys/tree.h>

#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_media.h>

#include <netinet/in.h>
#include <netinet/if_ether.h>

#if NBRIDGE > 0
#include <net/if_bridge.h>
#endif

#include <net80211/ieee80211_var.h>
#include <net80211/ieee80211_priv.h>

struct ieee80211_node *ieee80211_node_alloc(struct ieee80211com *);
void ieee80211_node_free(struct ieee80211com *, struct ieee80211_node *);
void ieee80211_node_copy(struct ieee80211com *, struct ieee80211_node *,
    const struct ieee80211_node *);
void ieee80211_choose_rsnparams(struct ieee80211com *);
u_int8_t ieee80211_node_getrssi(struct ieee80211com *,
    const struct ieee80211_node *);
int ieee80211_node_checkrssi(struct ieee80211com *,
    const struct ieee80211_node *);
int ieee80211_ess_is_better(struct ieee80211com *ic, struct ieee80211_node *,
    struct ieee80211_node *);
void ieee80211_node_set_timeouts(struct ieee80211_node *);
void ieee80211_setup_node(struct ieee80211com *, struct ieee80211_node *,
    const u_int8_t *);
struct ieee80211_node *ieee80211_alloc_node_helper(struct ieee80211com *);
void ieee80211_node_free_unref_cb(struct ieee80211_node *);
void ieee80211_node_tx_flushed(struct ieee80211com *, struct ieee80211_node *);
void ieee80211_node_switch_bss(struct ieee80211com *, struct ieee80211_node *);
void ieee80211_node_addba_request(struct ieee80211_node *, int);
void ieee80211_node_addba_request_ac_be_to(void *);
void ieee80211_node_addba_request_ac_bk_to(void *);
void ieee80211_node_addba_request_ac_vi_to(void *);
void ieee80211_node_addba_request_ac_vo_to(void *);
void ieee80211_needs_auth(struct ieee80211com *, struct ieee80211_node *);
#ifndef IEEE80211_STA_ONLY
void ieee80211_node_join_ht(struct ieee80211com *, struct ieee80211_node *);
void ieee80211_node_join_rsn(struct ieee80211com *, struct ieee80211_node *);
void ieee80211_node_join_11g(struct ieee80211com *, struct ieee80211_node *);
void ieee80211_node_leave_ht(struct ieee80211com *, struct ieee80211_node *);
void ieee80211_node_leave_vht(struct ieee80211com *, struct ieee80211_node *);
void ieee80211_node_leave_rsn(struct ieee80211com *, struct ieee80211_node *);
void ieee80211_node_leave_11g(struct ieee80211com *, struct ieee80211_node *);
void ieee80211_node_leave_pwrsave(struct ieee80211com *,
    struct ieee80211_node *);
void ieee80211_inact_timeout(void *);
void ieee80211_node_cache_timeout(void *);
#endif
void ieee80211_clean_inactive_nodes(struct ieee80211com *, int);

#ifndef IEEE80211_STA_ONLY
void
ieee80211_inact_timeout(void *arg)
{
    struct ieee80211com *ic = (typeof ic)arg;
    struct ieee80211_node *ni, *next_ni;
    int s;

    s = splnet();
    for (ni = RBT_MIN(ieee80211_tree, &ic->ic_tree);
        ni != NULL; ni = next_ni) {
        next_ni = RBT_NEXT(ieee80211_tree, ni);
        if (ni->ni_refcnt > 0)
            continue;
        if (ni->ni_inact < IEEE80211_INACT_MAX)
            ni->ni_inact++;
    }
    splx(s);

    timeout_add_sec(&ic->ic_inact_timeout, IEEE80211_INACT_WAIT);
}

void
ieee80211_node_cache_timeout(void *arg)
{
    struct ieee80211com *ic = (typeof ic)arg;

    ieee80211_clean_nodes(ic, 1);
    timeout_add_sec(&ic->ic_node_cache_timeout, IEEE80211_CACHE_WAIT);
}
#endif

/*
 * For debug purposes
 */
void
ieee80211_print_ess(struct ieee80211_ess *ess)
{
    ieee80211_print_essid(ess->essid, ess->esslen);
    if (ess->flags & IEEE80211_F_RSNON) {
        printf(" wpa");
        if (ess->rsnprotos & IEEE80211_PROTO_RSN)
            printf(",wpa2");
        if (ess->rsnprotos & IEEE80211_PROTO_WPA)
            printf(",wpa1");

        if (ess->rsnakms & IEEE80211_AKM_8021X ||
            ess->rsnakms & IEEE80211_AKM_SHA256_8021X)
            printf(",802.1x");
        printf(" ");

        if (ess->rsnciphers & IEEE80211_CIPHER_USEGROUP)
            printf(" usegroup");
        if (ess->rsnciphers & IEEE80211_CIPHER_WEP40)
            printf(" wep40");
        if (ess->rsnciphers & IEEE80211_CIPHER_WEP104)
            printf(" wep104");
        if (ess->rsnciphers & IEEE80211_CIPHER_TKIP)
            printf(" tkip");
        if (ess->rsnciphers & IEEE80211_CIPHER_CCMP)
            printf(" ccmp");
    }
    if (ess->flags & IEEE80211_F_WEPON) {
        int i = ess->def_txkey;

        printf(" wep,");
        if (ess->nw_keys[i].k_cipher & IEEE80211_CIPHER_WEP40)
            printf("wep40");
        if (ess->nw_keys[i].k_cipher & IEEE80211_CIPHER_WEP104)
            printf("wep104");
    }
    if (ess->flags == 0)
        printf(" clear");
    printf("\n");
}

void
ieee80211_print_ess_list(struct ieee80211com *ic)
{
    struct ifnet        *ifp = &ic->ic_if;
    struct ieee80211_ess    *ess;

    printf("%s: known networks\n", ifp->if_xname);
    TAILQ_FOREACH(ess, &ic->ic_ess, ess_next) {
        ieee80211_print_ess(ess);
    }
}

struct ieee80211_ess *
ieee80211_get_ess(struct ieee80211com *ic, const char *nwid, int len)
{
    struct ieee80211_ess    *ess;

    TAILQ_FOREACH(ess, &ic->ic_ess, ess_next) {
        if (len == ess->esslen &&
            memcmp(ess->essid, nwid, ess->esslen) == 0)
            return ess;
    }

    return NULL;
}

void
ieee80211_del_ess(struct ieee80211com *ic, char *nwid, int len, int all)
{
    struct ieee80211_ess *ess, *next;

    TAILQ_FOREACH_SAFE(ess, &ic->ic_ess, ess_next, next) {
        if (all == 1 || (ess->esslen == len &&
            memcmp(ess->essid, nwid, len) == 0)) {
            TAILQ_REMOVE(&ic->ic_ess, ess, ess_next);
            explicit_bzero(ess, sizeof(*ess));
            free(ess, M_DEVBUF, sizeof(*ess));
            if (TAILQ_EMPTY(&ic->ic_ess))
                ic->ic_flags &= ~IEEE80211_F_AUTO_JOIN;
            if (all != 1)
                return;
        }
    }
}

/* Keep in sync with ieee80211_ioctl.c:ieee80211_ioctl_setnwkeys() */
static int
ieee80211_ess_setnwkeys(struct ieee80211_ess *ess,
    const struct ieee80211_nwkey *nwkey)
{
    struct ieee80211_key *k;
    int error, i;

    if (nwkey->i_wepon == IEEE80211_NWKEY_OPEN) {
        if (!(ess->flags & IEEE80211_F_WEPON))
            return 0;
        ess->flags &= ~IEEE80211_F_WEPON;
        return ENETRESET;
    }
    if (nwkey->i_defkid < 1 || nwkey->i_defkid > IEEE80211_WEP_NKID)
        return EINVAL;

    for (i = 0; i < IEEE80211_WEP_NKID; i++) {
        if (nwkey->i_key[i].i_keylen == 0 ||
            nwkey->i_key[i].i_keydat == NULL)
            continue;    /* entry not set */
        if (nwkey->i_key[i].i_keylen > IEEE80211_KEYBUF_SIZE)
            return EINVAL;

        /* map wep key to ieee80211_key */
        k = &ess->nw_keys[i];
        memset(k, 0, sizeof(*k));
        if (nwkey->i_key[i].i_keylen <= 5)
            k->k_cipher = IEEE80211_CIPHER_WEP40;
        else
            k->k_cipher = IEEE80211_CIPHER_WEP104;
        k->k_len = ieee80211_cipher_keylen(k->k_cipher);
        k->k_flags = IEEE80211_KEY_GROUP | IEEE80211_KEY_TX;
        error = copyin(nwkey->i_key[i].i_keydat, k->k_key, k->k_len);
        if (error != 0)
            return error;
    }
    ess->def_txkey = nwkey->i_defkid - 1;
    ess->flags |= IEEE80211_F_WEPON;

    return ENETRESET;
}


/* Keep in sync with ieee80211_ioctl.c:ieee80211_ioctl_setwpaparms() */
static int
ieee80211_ess_setwpaparms(struct ieee80211_ess *ess,
    const struct ieee80211_wpaparams *wpa)
{
    if (!wpa->i_enabled) {
        if (!(ess->flags & IEEE80211_F_RSNON))
            return 0;
        ess->flags &= ~IEEE80211_F_RSNON;
        ess->rsnprotos = 0;
        ess->rsnakms = 0;
        ess->rsngroupcipher = (typeof ess->rsngroupcipher)0;
        ess->rsnciphers = 0;
        return ENETRESET;
    }

    ess->rsnprotos = 0;
    if (wpa->i_protos & IEEE80211_WPA_PROTO_WPA1)
        ess->rsnprotos |= IEEE80211_PROTO_WPA;
    if (wpa->i_protos & IEEE80211_WPA_PROTO_WPA2)
        ess->rsnprotos |= IEEE80211_PROTO_RSN;
    if (ess->rsnprotos == 0)    /* set to default (RSN) */
        ess->rsnprotos = IEEE80211_PROTO_RSN;

    ess->rsnakms = 0;
    if (wpa->i_akms & IEEE80211_WPA_AKM_PSK)
        ess->rsnakms |= IEEE80211_AKM_PSK;
    if (wpa->i_akms & IEEE80211_WPA_AKM_SHA256_PSK)
        ess->rsnakms |= IEEE80211_AKM_SHA256_PSK;
    if (wpa->i_akms & IEEE80211_WPA_AKM_8021X)
        ess->rsnakms |= IEEE80211_AKM_8021X;
    if (wpa->i_akms & IEEE80211_WPA_AKM_SHA256_8021X)
        ess->rsnakms |= IEEE80211_AKM_SHA256_8021X;
    if (ess->rsnakms == 0)    /* set to default (PSK) */
        ess->rsnakms = IEEE80211_AKM_PSK;

    if (wpa->i_groupcipher == IEEE80211_WPA_CIPHER_WEP40)
        ess->rsngroupcipher = IEEE80211_CIPHER_WEP40;
    else if (wpa->i_groupcipher == IEEE80211_WPA_CIPHER_TKIP)
        ess->rsngroupcipher = IEEE80211_CIPHER_TKIP;
    else if (wpa->i_groupcipher == IEEE80211_WPA_CIPHER_CCMP)
        ess->rsngroupcipher = IEEE80211_CIPHER_CCMP;
    else if (wpa->i_groupcipher == IEEE80211_WPA_CIPHER_WEP104)
        ess->rsngroupcipher = IEEE80211_CIPHER_WEP104;
    else  {    /* set to default */
        if (ess->rsnprotos & IEEE80211_PROTO_WPA)
            ess->rsngroupcipher = IEEE80211_CIPHER_TKIP;
        else
            ess->rsngroupcipher = IEEE80211_CIPHER_CCMP;
    }

    ess->rsnciphers = 0;
    if (wpa->i_ciphers & IEEE80211_WPA_CIPHER_TKIP)
        ess->rsnciphers |= IEEE80211_CIPHER_TKIP;
    if (wpa->i_ciphers & IEEE80211_WPA_CIPHER_CCMP)
        ess->rsnciphers |= IEEE80211_CIPHER_CCMP;
    if (wpa->i_ciphers & IEEE80211_WPA_CIPHER_USEGROUP)
        ess->rsnciphers = IEEE80211_CIPHER_USEGROUP;
    if (ess->rsnciphers == 0) { /* set to default (CCMP, TKIP if WPA1) */
        ess->rsnciphers = IEEE80211_CIPHER_CCMP;
        if (ess->rsnprotos & IEEE80211_PROTO_WPA)
            ess->rsnciphers |= IEEE80211_CIPHER_TKIP;
    }

    ess->flags |= IEEE80211_F_RSNON;

    if (ess->rsnakms &
        (IEEE80211_AKM_8021X|IEEE80211_WPA_AKM_SHA256_8021X))
        ess->flags |= IEEE80211_JOIN_8021X;

    return ENETRESET;
}

static void
ieee80211_ess_clear_wep(struct ieee80211_ess *ess)
{
    int i;

    /* Disable WEP */
    for (i = 0; i < IEEE80211_WEP_NKID; i++) {
        explicit_bzero(&ess->nw_keys[i], sizeof(ess->nw_keys[0]));
    }
    ess->def_txkey = 0;
    ess->flags &= ~IEEE80211_F_WEPON;
}

static void
ieee80211_ess_clear_wpa(struct ieee80211_ess *ess)
{
    /* Disable WPA */
    ess->rsnprotos = ess->rsnakms =
        ess->rsnciphers = 0;
    ess->rsngroupcipher = (typeof ess->rsngroupcipher)0;
    explicit_bzero(ess->psk, sizeof(ess->psk));
    ess->flags &= ~(IEEE80211_F_PSK | IEEE80211_F_RSNON);
}

int
ieee80211_add_ess(struct ieee80211com *ic, struct ieee80211_join *join)
{
    struct ieee80211_ess *ess;
    int _new = 0, ness = 0;

    /* only valid for station (aka, client) mode */
    if (ic->ic_opmode != IEEE80211_M_STA)
        return (0);

    TAILQ_FOREACH(ess, &ic->ic_ess, ess_next) {
        if (ess->esslen == join->i_len &&
            memcmp(ess->essid, join->i_nwid, ess->esslen) == 0)
            break;
        ness++;
    }

    if (ess == NULL) {
        /* if not found, and wpa/wep are set, then return */
        if ((join->i_flags & IEEE80211_JOIN_WPA) &&
            (join->i_flags & IEEE80211_JOIN_NWKEY)) {
            return (EINVAL);
        }
        if (ness > IEEE80211_CACHE_SIZE)
            return (ERANGE);
        _new = 1;
        ess = (typeof ess)malloc(sizeof(*ess), M_DEVBUF, M_NOWAIT|M_ZERO);
        if (ess == NULL)
            return (ENOMEM);
        memcpy(ess->essid, join->i_nwid, join->i_len);
        ess->esslen = join->i_len;
    }

    if (join->i_flags & IEEE80211_JOIN_WPA) {
        if (join->i_wpaparams.i_enabled) {
            if (!(ic->ic_caps & IEEE80211_C_RSN)) {
                free(ess, M_DEVBUF, sizeof(*ess));
                return ENODEV;
            }
            ieee80211_ess_setwpaparms(ess,
                &join->i_wpaparams);
            if (join->i_flags & IEEE80211_JOIN_WPAPSK) {
                ess->flags |= IEEE80211_F_PSK;
                explicit_bzero(ess->psk, sizeof(ess->psk));
                memcpy(ess->psk, &join->i_wpapsk.i_psk,
                    sizeof(ess->psk));
            }
            ieee80211_ess_clear_wep(ess);
        } else {
            ieee80211_ess_clear_wpa(ess);
        }
    } else if (join->i_flags & IEEE80211_JOIN_NWKEY) {
        if (join->i_nwkey.i_wepon) {
            if (!(ic->ic_caps & IEEE80211_C_WEP)) {
                free(ess, M_DEVBUF, sizeof(*ess));
                return ENODEV;
            }
            ieee80211_ess_setnwkeys(ess, &join->i_nwkey);
            ieee80211_ess_clear_wpa(ess);
        } else {
            ieee80211_ess_clear_wep(ess);
        }
    }

    if (_new)
        TAILQ_INSERT_TAIL(&ic->ic_ess, ess, ess_next);

    return (0);
}

uint8_t
ieee80211_ess_adjust_rssi(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    uint8_t rssi = ni->ni_rssi;

    /*
     * Slightly punish 2 GHz RSSI values since they are usually
     * stronger than 5 GHz RSSI values.
     */
    if (IEEE80211_IS_CHAN_2GHZ(ni->ni_chan)) {
        if (ic->ic_max_rssi) {
            uint8_t p = (5 * ic->ic_max_rssi) / 100;
             if (rssi >= p)
                rssi -= p; /* punish by 5% */
        } else  {
            if (rssi >= 8)
                rssi -= 8; /* punish by 8 dBm */
        }
    }

    return rssi;
}

int
ieee80211_ess_calculate_score(struct ieee80211com *ic,
    struct ieee80211_node *ni)
{
    int score = 0;
    uint8_t    min_5ghz_rssi;

    if (ic->ic_max_rssi)
        min_5ghz_rssi = IEEE80211_RSSI_THRES_RATIO_5GHZ;
    else
        min_5ghz_rssi = (uint8_t)IEEE80211_RSSI_THRES_5GHZ;

    /* not using join any */
    if (ieee80211_get_ess(ic, (const char*)ni->ni_essid, ni->ni_esslen))
        score += 32;

    /* Calculate the crypto score */
    if (ni->ni_rsnprotos & IEEE80211_PROTO_RSN)
        score += 16;
    if (ni->ni_rsnprotos & IEEE80211_PROTO_WPA)
        score += 8;
    if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY)
        score += 4;

    /* 5GHz with a good signal */
    if (IEEE80211_IS_CHAN_5GHZ(ni->ni_chan) &&
        ni->ni_rssi > min_5ghz_rssi)
        score += 2;

    /* HT/VHT available */
    if (ieee80211_node_supports_ht(ni))
        score++;
    if (ieee80211_node_supports_vht(ni))
        score++;

    /* Boost this AP if it had no auth/assoc failures in the past. */
    if (ni->ni_fails == 0)
        score += 21;

    return score;
}

/*
 * Given two APs, determine the "better" one of the two.
 * We compute a score based on the following attributes:
 *
 *  crypto: wpa2 > wpa1 > wep > open
 *  band: 5 GHz > 2 GHz provided 5 GHz rssi is above threshold
 *  supported standard revisions: 11ac > 11n > 11a/b/g
 *  rssi: rssi1 > rssi2 as a numeric comparison with a slight
 *         disadvantage for 2 GHz APs
 *
 * Crypto carries most weight, followed by band, followed by rssi.
 */
int
ieee80211_ess_is_better(struct ieee80211com *ic,
    struct ieee80211_node *nicur, struct ieee80211_node *nican)
{
    struct ifnet        *ifp = &ic->ic_if;
    int             score_cur = 0, score_can = 0;
    int             cur_rssi, can_rssi;

    score_cur = ieee80211_ess_calculate_score(ic, nicur);
    score_can = ieee80211_ess_calculate_score(ic, nican);

    cur_rssi = ieee80211_ess_adjust_rssi(ic, nicur);
    can_rssi = ieee80211_ess_adjust_rssi(ic, nican);

    if (can_rssi > cur_rssi)
        score_can++;

    if ((ifp->if_flags & IFF_DEBUG) && (score_can <= score_cur)) {
        printf("%s: AP %s ", ifp->if_xname,
            ether_sprintf(nican->ni_bssid));
        ieee80211_print_essid(nican->ni_essid, nican->ni_esslen);
        printf(" score %d\n", score_can);
    }

    return score_can > score_cur;
}

/* Determine whether a candidate AP belongs to a given ESS. */
int
ieee80211_match_ess(struct ieee80211_ess *ess, struct ieee80211_node *ni)
{
    if (ess->esslen != 0 &&
        (ess->esslen != ni->ni_esslen ||
        memcmp(ess->essid, ni->ni_essid, ess->esslen) != 0)) {
        ni->ni_assoc_fail |= IEEE80211_NODE_ASSOCFAIL_ESSID;
        return 0;
    }

    if (ess->flags & (IEEE80211_F_PSK | IEEE80211_F_RSNON)) {
        /* Ensure same WPA version. */
        if ((ni->ni_rsnprotos & IEEE80211_PROTO_RSN) &&
            (ess->rsnprotos & IEEE80211_PROTO_RSN) == 0) {
            ni->ni_assoc_fail |= IEEE80211_NODE_ASSOCFAIL_WPA_PROTO;
            return 0;
        }
        if ((ni->ni_rsnprotos & IEEE80211_PROTO_WPA) &&
            (ess->rsnprotos & IEEE80211_PROTO_WPA) == 0) {
            ni->ni_assoc_fail |= IEEE80211_NODE_ASSOCFAIL_WPA_PROTO;
            return 0;
        }
    } else if (ess->flags & IEEE80211_F_WEPON) {
        if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) {
            ni->ni_assoc_fail |= IEEE80211_NODE_ASSOCFAIL_PRIVACY;
            return 0;
        }
    } else {
        if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) != 0) {
            ni->ni_assoc_fail |= IEEE80211_NODE_ASSOCFAIL_PRIVACY;
            return 0;
        }
    }

    if (ess->esslen == 0 &&
        (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) != 0) {
        ni->ni_assoc_fail |= IEEE80211_NODE_ASSOCFAIL_PRIVACY;
        return 0;
    }

    return 1;
}

void
ieee80211_switch_ess(struct ieee80211com *ic)
{
    struct ifnet        *ifp = &ic->ic_if;
    struct ieee80211_ess    *ess, *seless = NULL;
    struct ieee80211_node    *ni, *selni = NULL;

    if (!ISSET(ifp->if_flags, IFF_RUNNING))
        return;

    /* Find the best AP matching an entry on our ESS join list. */
    RBT_FOREACH(ni, ieee80211_tree, &ic->ic_tree) {
        if ((ic->ic_flags & IEEE80211_F_DESBSSID) &&
            !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid))
            continue;

        TAILQ_FOREACH(ess, &ic->ic_ess, ess_next) {
            if (ieee80211_match_ess(ess, ni))
                break;
        }
        if (ess == NULL)
            continue;

        /*
         * Operate only on ic_des_essid if auto-join is disabled.
         * We might have a password stored for this network.
         */
        if (!ISSET(ic->ic_flags, IEEE80211_F_AUTO_JOIN)) {
            if (ic->ic_des_esslen == ni->ni_esslen &&
                memcmp(ic->ic_des_essid, ni->ni_essid,
                ni->ni_esslen) == 0) {
                ieee80211_set_ess(ic, ess, ni);
                return;
            }
            continue;
        }

        if (selni == NULL) {
            seless = ess;
            selni = ni;
            continue;
        }

        if (ieee80211_ess_is_better(ic, selni, ni)) {
            seless = ess;
            selni = ni;
        }
    }

    if (selni && seless && !(selni->ni_esslen == ic->ic_des_esslen &&
        (memcmp(ic->ic_des_essid, selni->ni_essid,
         IEEE80211_NWID_LEN) == 0))) {
        if (ifp->if_flags & IFF_DEBUG) {
            printf("%s: best AP %s ", ifp->if_xname,
                ether_sprintf(selni->ni_bssid));
            ieee80211_print_essid(selni->ni_essid,
                selni->ni_esslen);
            printf(" score %d\n",
                ieee80211_ess_calculate_score(ic, selni));
            printf("%s: switching to network ", ifp->if_xname);
            ieee80211_print_essid(selni->ni_essid,
                selni->ni_esslen);
            if (seless->esslen == 0)
                printf(" via join any");
            printf("\n");

        }
        ieee80211_set_ess(ic, seless, selni);
    }
}

void
ieee80211_set_ess(struct ieee80211com *ic, struct ieee80211_ess *ess,
    struct ieee80211_node *ni)
{
    memset(ic->ic_des_essid, 0, IEEE80211_NWID_LEN);
    ic->ic_des_esslen = ni->ni_esslen;
    memcpy(ic->ic_des_essid, ni->ni_essid, ic->ic_des_esslen);

    ieee80211_disable_wep(ic);
    ieee80211_disable_rsn(ic);

    if (ess->flags & IEEE80211_F_RSNON) {
        explicit_bzero(ic->ic_psk, sizeof(ic->ic_psk));
        memcpy(ic->ic_psk, ess->psk, sizeof(ic->ic_psk));

        ic->ic_rsnprotos = ess->rsnprotos;
        ic->ic_rsnakms = ess->rsnakms;
        ic->ic_rsngroupcipher = ess->rsngroupcipher;
        ic->ic_rsnciphers = ess->rsnciphers;
        ic->ic_flags |= IEEE80211_F_RSNON;
        if (ess->flags & IEEE80211_F_PSK)
            ic->ic_flags |= IEEE80211_F_PSK;
    } else if (ess->flags & IEEE80211_F_WEPON) {
        struct ieee80211_key    *k;
        int             i;

        for (i = 0; i < IEEE80211_WEP_NKID; i++) {
            k = &ic->ic_nw_keys[i];
            if (k->k_cipher != IEEE80211_CIPHER_NONE)
                (*ic->ic_delete_key)(ic, NULL, k);
            memcpy(&ic->ic_nw_keys[i], &ess->nw_keys[i],
                sizeof(struct ieee80211_key));
            if (k->k_cipher != IEEE80211_CIPHER_NONE)
                (*ic->ic_set_key)(ic, NULL, k);
        }
        ic->ic_def_txkey = ess->def_txkey;
        ic->ic_flags |= IEEE80211_F_WEPON;
    }
}

void
ieee80211_deselect_ess(struct ieee80211com *ic)
{
    memset(ic->ic_des_essid, 0, IEEE80211_NWID_LEN);
    ic->ic_des_esslen = 0;
    ieee80211_disable_wep(ic);
    ieee80211_disable_rsn(ic);
}

void
ieee80211_node_attach(struct ifnet *ifp)
{
    struct ieee80211com *ic = (typeof ic)ifp;
#ifndef IEEE80211_STA_ONLY
    int size;
#endif

    RBT_INIT(ieee80211_tree, &ic->ic_tree);
    ic->ic_node_alloc = ieee80211_node_alloc;
    ic->ic_node_free = ieee80211_node_free;
    ic->ic_node_copy = ieee80211_node_copy;
    ic->ic_node_getrssi = ieee80211_node_getrssi;
    ic->ic_node_checkrssi = ieee80211_node_checkrssi;
    ic->ic_scangen = 1;
    ic->ic_max_nnodes = ieee80211_cache_size;

    if (ic->ic_max_aid == 0)
        ic->ic_max_aid = IEEE80211_AID_DEF;
    else if (ic->ic_max_aid > IEEE80211_AID_MAX)
        ic->ic_max_aid = IEEE80211_AID_MAX;
#ifndef IEEE80211_STA_ONLY
    size = howmany(ic->ic_max_aid, 32) * sizeof(u_int32_t);
    ic->ic_aid_bitmap = (typeof ic->ic_aid_bitmap)malloc(size, M_DEVBUF, M_NOWAIT | M_ZERO);
    if (ic->ic_aid_bitmap == NULL) {
        /* XXX no way to recover */
        printf("%s: no memory for AID bitmap!\n", __func__);
        ic->ic_max_aid = 0;
    }
    if (ic->ic_caps & (IEEE80211_C_HOSTAP | IEEE80211_C_IBSS)) {
        ic->ic_tim_len = howmany(ic->ic_max_aid, 8);
        ic->ic_tim_bitmap = (typeof ic->ic_tim_bitmap)malloc(ic->ic_tim_len, M_DEVBUF,
            M_NOWAIT | M_ZERO);
        if (ic->ic_tim_bitmap == NULL) {
            printf("%s: no memory for TIM bitmap!\n", __func__);
            ic->ic_tim_len = 0;
        } else
            ic->ic_set_tim = ieee80211_set_tim;
        timeout_set(&ic->ic_rsn_timeout,
            ieee80211_gtk_rekey_timeout, ic);
        timeout_set(&ic->ic_inact_timeout,
            ieee80211_inact_timeout, ic);
        timeout_set(&ic->ic_node_cache_timeout,
            ieee80211_node_cache_timeout, ic);
    }
#endif
    TAILQ_INIT(&ic->ic_ess);
}

struct ieee80211_node *
ieee80211_alloc_node_helper(struct ieee80211com *ic)
{
    struct ieee80211_node *ni;
    if (ic->ic_nnodes >= ic->ic_max_nnodes)
        ieee80211_clean_nodes(ic, 0);
    if (ic->ic_nnodes >= ic->ic_max_nnodes)
        return NULL;
    ni = (*ic->ic_node_alloc)(ic);
    return ni;
}

void
ieee80211_node_lateattach(struct ifnet *ifp)
{
    struct ieee80211com *ic = (typeof ic)ifp;
    struct ieee80211_node *ni;

    ni = ieee80211_alloc_node_helper(ic);
    if (ni == NULL)
        panic("unable to setup initial BSS node");
    ni->ni_chan = IEEE80211_CHAN_ANYC;
    ic->ic_bss = ieee80211_ref_node(ni);
    ic->ic_txpower = IEEE80211_TXPOWER_MAX;
#ifndef IEEE80211_STA_ONLY
    mq_init(&ni->ni_savedq, IEEE80211_PS_MAX_QUEUE, IPL_NET);
#endif
}

void
ieee80211_node_detach(struct ifnet *ifp)
{
    struct ieee80211com *ic = (typeof ic)ifp;

    if (ic->ic_bss != NULL) {
        (*ic->ic_node_free)(ic, ic->ic_bss);
        ic->ic_bss = NULL;
    }
    ieee80211_del_ess(ic, NULL, 0, 1);
    ieee80211_free_allnodes(ic, 1);
#ifndef IEEE80211_STA_ONLY
    free(ic->ic_aid_bitmap, M_DEVBUF,
        howmany(ic->ic_max_aid, 32) * sizeof(u_int32_t));
    free(ic->ic_tim_bitmap, M_DEVBUF, ic->ic_tim_len);
    timeout_del(&ic->ic_inact_timeout);
    timeout_del(&ic->ic_node_cache_timeout);
    timeout_del(&ic->ic_tkip_micfail_timeout);
#endif
    timeout_del(&ic->ic_rsn_timeout);
}

/*
 * AP scanning support.
 */

/*
 * Initialize the active channel set based on the set
 * of available channels and the current PHY mode.
 */
void
ieee80211_reset_scan(struct ifnet *ifp)
{
    struct ieee80211com *ic = (typeof ic)ifp;

    memcpy(ic->ic_chan_scan, ic->ic_chan_active,
        sizeof(ic->ic_chan_active));
    /* NB: hack, setup so next_scan starts with the first channel */
    if (ic->ic_bss != NULL && ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC)
        ic->ic_bss->ni_chan = &ic->ic_channels[IEEE80211_CHAN_MAX];
}

/*
 * Increase a node's inactivity counter.
 * This counter get reset to zero if a frame is received.
 * This function is intended for station mode only.
 * See ieee80211_node_cache_timeout() for hostap mode.
 */
void
ieee80211_node_raise_inact(void *arg, struct ieee80211_node *ni)
{
    if (ni->ni_refcnt == 0 && ni->ni_inact < IEEE80211_INACT_SCAN)
        ni->ni_inact++;
}

/*
 * Begin an active scan.
 */
void
ieee80211_begin_scan(struct ifnet *ifp)
{
    struct ieee80211com *ic = (typeof ic)ifp;

    /*
     * In all but hostap mode scanning starts off in
     * an active mode before switching to passive.
     */
#ifndef IEEE80211_STA_ONLY
    if (ic->ic_opmode != IEEE80211_M_HOSTAP)
#endif
    {
        ic->ic_flags |= IEEE80211_F_ASCAN;
        ic->ic_stats.is_scan_active++;
    }
#ifndef IEEE80211_STA_ONLY
    else
        ic->ic_stats.is_scan_passive++;
#endif
    if (ifp->if_flags & IFF_DEBUG)
        printf("%s: begin %s scan\n", ifp->if_xname,
            (ic->ic_flags & IEEE80211_F_ASCAN) ?
                "active" : "passive");


    if (ic->ic_opmode == IEEE80211_M_STA) {
        ieee80211_node_cleanup(ic, ic->ic_bss);
        ieee80211_iterate_nodes(ic, ieee80211_node_raise_inact, NULL);
    }

    /*
     * Reset the current mode. Setting the current mode will also
     * reset scan state.
     */
    if (IFM_MODE(ic->ic_media.ifm_cur->ifm_media) == IFM_AUTO)
        ic->ic_curmode = IEEE80211_MODE_AUTO;
    ieee80211_setmode(ic, (enum ieee80211_phymode)ic->ic_curmode);

    ic->ic_scan_count = 0;

    /* Scan the next channel. */
    ieee80211_next_scan(ifp);
}

/*
 * Switch to the next channel marked for scanning.
 */
void
ieee80211_next_scan(struct ifnet *ifp)
{
    struct ieee80211com *ic = (typeof ic)ifp;
    struct ieee80211_channel *chan;

    chan = ic->ic_bss->ni_chan;
    for (;;) {
        if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX])
            chan = &ic->ic_channels[0];
        if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) {
            /*
             * Ignore channels marked passive-only
             * during an active scan.
             */
            if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 ||
                (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0)
                break;
        }
        if (chan == ic->ic_bss->ni_chan) {
            ieee80211_end_scan(ifp);
            return;
        }
    }
    clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan));
    DPRINTF(("chan %d->%d\n",
        ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan),
        ieee80211_chan2ieee(ic, chan)));
    ic->ic_bss->ni_chan = chan;
    ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
}

#ifndef IEEE80211_STA_ONLY
void
ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan)
{
    enum ieee80211_phymode mode;
    struct ieee80211_node *ni;
    struct ifnet *ifp = &ic->ic_if;

    ni = ic->ic_bss;
    if (ifp->if_flags & IFF_DEBUG)
        printf("%s: creating ibss\n", ifp->if_xname);
    ic->ic_flags |= IEEE80211_F_SIBSS;
    ni->ni_chan = chan;
    if ((ic->ic_flags & IEEE80211_F_VHTON) && IEEE80211_IS_CHAN_5GHZ(chan))
        mode = IEEE80211_MODE_11AC;
    else if (ic->ic_flags & IEEE80211_F_HTON)
        mode = IEEE80211_MODE_11N;
    else
        mode = ieee80211_chan2mode(ic, ni->ni_chan);
    ieee80211_setmode(ic, mode);
    /* Pick an appropriate mode for supported legacy rates. */
    if (ic->ic_curmode == IEEE80211_MODE_11AC) {
        mode = IEEE80211_MODE_11A;
    } else if (ic->ic_curmode == IEEE80211_MODE_11N) {
        if (IEEE80211_IS_CHAN_5GHZ(chan))
            mode = IEEE80211_MODE_11A;
        else
            mode = IEEE80211_MODE_11G;
    } else {
        mode = (typeof mode)ic->ic_curmode;
    }
    ni->ni_rates = ic->ic_sup_rates[mode];
    ni->ni_txrate = 0;
    IEEE80211_ADDR_COPY(ni->ni_macaddr, ic->ic_myaddr);
    IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr);
    if (ic->ic_opmode == IEEE80211_M_IBSS) {
        if ((ic->ic_flags & IEEE80211_F_DESBSSID) != 0)
            IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_des_bssid);
        else
            ni->ni_bssid[0] |= 0x02;    /* local bit for IBSS */
    }
    ni->ni_esslen = ic->ic_des_esslen;
    memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen);
    ni->ni_rssi = 0;
    ni->ni_rstamp = 0;
    memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp));
    ni->ni_intval = ic->ic_lintval;
    ni->ni_capinfo = IEEE80211_CAPINFO_IBSS;
    if (ic->ic_flags & IEEE80211_F_WEPON)
        ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY;
    if (ic->ic_flags & IEEE80211_F_HTON) {
        const struct ieee80211_edca_ac_params *ac_qap;
        struct ieee80211_edca_ac_params *ac;
        int aci;

        /*
         * Configure HT protection. This will be updated later
         * based on the number of non-HT nodes in the node cache.
         */
        ic->ic_protmode = IEEE80211_PROT_NONE;
        ni->ni_htop1 = IEEE80211_HTPROT_NONE;
        /* Disallow Greenfield mode. None of our drivers support it. */
        ni->ni_htop1 |= IEEE80211_HTOP1_NONGF_STA;
        if (ic->ic_updateprot)
            ic->ic_updateprot(ic);

        /* Configure QoS EDCA parameters. */
        for (aci = 0; aci < EDCA_NUM_AC; aci++) {
            ac = &ic->ic_edca_ac[aci];
            ac_qap = &ieee80211_qap_edca_table[ic->ic_curmode][aci];
            ac->ac_acm       = ac_qap->ac_acm;
            ac->ac_aifsn     = ac_qap->ac_aifsn;
            ac->ac_ecwmin    = ac_qap->ac_ecwmin;
            ac->ac_ecwmax    = ac_qap->ac_ecwmax;
            ac->ac_txoplimit = ac_qap->ac_txoplimit;
        }
        if (ic->ic_updateedca)
            (*ic->ic_updateedca)(ic);
    }
    if (ic->ic_flags & IEEE80211_F_RSNON) {
        struct ieee80211_key *k;

        /* initialize 256-bit global key counter to a random value */
        arc4random_buf(ic->ic_globalcnt, EAPOL_KEY_NONCE_LEN);

        ni->ni_rsnprotos = ic->ic_rsnprotos;
        ni->ni_rsnakms = ic->ic_rsnakms;
        ni->ni_rsnciphers = ic->ic_rsnciphers;
        ni->ni_rsngroupcipher = ic->ic_rsngroupcipher;
        ni->ni_rsngroupmgmtcipher = ic->ic_rsngroupmgmtcipher;
        ni->ni_rsncaps = 0;
        if (ic->ic_caps & IEEE80211_C_MFP) {
            ni->ni_rsncaps |= IEEE80211_RSNCAP_MFPC;
            if (ic->ic_flags & IEEE80211_F_MFPR)
                ni->ni_rsncaps |= IEEE80211_RSNCAP_MFPR;
        }

        ic->ic_def_txkey = 1;
        ic->ic_flags &= ~IEEE80211_F_COUNTERM;
        k = &ic->ic_nw_keys[ic->ic_def_txkey];
        memset(k, 0, sizeof(*k));
        k->k_id = ic->ic_def_txkey;
        k->k_cipher = ni->ni_rsngroupcipher;
        k->k_flags = IEEE80211_KEY_GROUP | IEEE80211_KEY_TX;
        k->k_len = ieee80211_cipher_keylen(k->k_cipher);
        arc4random_buf(k->k_key, k->k_len);
        (*ic->ic_set_key)(ic, ni, k);    /* XXX */

        if (ic->ic_caps & IEEE80211_C_MFP) {
            ic->ic_igtk_kid = 4;
            k = &ic->ic_nw_keys[ic->ic_igtk_kid];
            memset(k, 0, sizeof(*k));
            k->k_id = ic->ic_igtk_kid;
            k->k_cipher = ni->ni_rsngroupmgmtcipher;
            k->k_flags = IEEE80211_KEY_IGTK | IEEE80211_KEY_TX;
            k->k_len = 16;
            arc4random_buf(k->k_key, k->k_len);
            (*ic->ic_set_key)(ic, ni, k);    /* XXX */
        }
        /*
         * In HostAP mode, multicast traffic is sent using ic_bss
         * as the Tx node, so mark our node as valid so we can send
         * multicast frames using the group key we've just configured.
         */
        ni->ni_port_valid = 1;
        ni->ni_flags |= IEEE80211_NODE_TXPROT;

        /* schedule a GTK/IGTK rekeying after 3600s */
        timeout_add_sec(&ic->ic_rsn_timeout, 3600);
    }
    timeout_add_sec(&ic->ic_inact_timeout, IEEE80211_INACT_WAIT);
    timeout_add_sec(&ic->ic_node_cache_timeout, IEEE80211_CACHE_WAIT);
    ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
}
#endif    /* IEEE80211_STA_ONLY */

int
ieee80211_match_bss(struct ieee80211com *ic, struct ieee80211_node *ni,
    int bgscan)
{
    u_int8_t rate;
    int fail;

    fail = 0;
    if ((ic->ic_flags & IEEE80211_F_BGSCAN) == 0 &&
        isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan)))
        fail |= IEEE80211_NODE_ASSOCFAIL_CHAN;
    if (ic->ic_des_chan != IEEE80211_CHAN_ANYC &&
        ni->ni_chan != ic->ic_des_chan)
        fail |= IEEE80211_NODE_ASSOCFAIL_CHAN;
#ifndef IEEE80211_STA_ONLY
    if (ic->ic_opmode == IEEE80211_M_IBSS) {
        if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
            fail |= IEEE80211_NODE_ASSOCFAIL_IBSS;
    } else
#endif
    {
        if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0)
            fail |= IEEE80211_NODE_ASSOCFAIL_IBSS;
    }
    if (ic->ic_flags & (IEEE80211_F_WEPON | IEEE80211_F_RSNON)) {
        if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
            fail |= IEEE80211_NODE_ASSOCFAIL_PRIVACY;
    } else {
        if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY)
            fail |= IEEE80211_NODE_ASSOCFAIL_PRIVACY;
    }

    rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO);
    if (rate & IEEE80211_RATE_BASIC)
        fail |= IEEE80211_NODE_ASSOCFAIL_BASIC_RATE;
    if (ic->ic_des_esslen == 0)
        fail |= IEEE80211_NODE_ASSOCFAIL_ESSID;
    if (ic->ic_des_esslen != 0 &&
        (ni->ni_esslen != ic->ic_des_esslen ||
         memcmp(ni->ni_essid, ic->ic_des_essid, ic->ic_des_esslen) != 0))
        fail |= IEEE80211_NODE_ASSOCFAIL_ESSID;
    if ((ic->ic_flags & IEEE80211_F_DESBSSID) &&
        !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid))
        fail |= IEEE80211_NODE_ASSOCFAIL_BSSID;

    if (ic->ic_flags & IEEE80211_F_RSNON) {
        /*
         * If at least one RSN IE field from the AP's RSN IE fails
         * to overlap with any value the STA supports, the STA shall
         * decline to associate with that AP.
         */
        if ((ni->ni_rsnprotos & ic->ic_rsnprotos) == 0)
            fail |= IEEE80211_NODE_ASSOCFAIL_WPA_PROTO;
        if ((ni->ni_rsnakms & ic->ic_rsnakms) == 0)
            fail |= IEEE80211_NODE_ASSOCFAIL_WPA_PROTO;
        if ((ni->ni_rsnakms & ic->ic_rsnakms &
             ~(IEEE80211_AKM_PSK | IEEE80211_AKM_SHA256_PSK)) == 0) {
            /* AP only supports PSK AKMPs */
            if (!(ic->ic_flags & IEEE80211_F_PSK))
                fail |= IEEE80211_NODE_ASSOCFAIL_WPA_PROTO;
        }
        if (ni->ni_rsngroupcipher != IEEE80211_CIPHER_WEP40 &&
            ni->ni_rsngroupcipher != IEEE80211_CIPHER_TKIP &&
            ni->ni_rsngroupcipher != IEEE80211_CIPHER_CCMP &&
            ni->ni_rsngroupcipher != IEEE80211_CIPHER_WEP104)
            fail |= IEEE80211_NODE_ASSOCFAIL_WPA_PROTO;
        if ((ni->ni_rsnciphers & ic->ic_rsnciphers) == 0)
            fail |= IEEE80211_NODE_ASSOCFAIL_WPA_PROTO;

        /* we only support BIP as the IGTK cipher */
        if ((ni->ni_rsncaps & IEEE80211_RSNCAP_MFPC) &&
            ni->ni_rsngroupmgmtcipher != IEEE80211_CIPHER_BIP)
            fail |= IEEE80211_NODE_ASSOCFAIL_WPA_PROTO;

        /* we do not support MFP but AP requires it */
        if (!(ic->ic_caps & IEEE80211_C_MFP) &&
            (ni->ni_rsncaps & IEEE80211_RSNCAP_MFPR))
            fail |= IEEE80211_NODE_ASSOCFAIL_WPA_PROTO;

        /* we require MFP but AP does not support it */
        if ((ic->ic_caps & IEEE80211_C_MFP) &&
            (ic->ic_flags & IEEE80211_F_MFPR) &&
            !(ni->ni_rsncaps & IEEE80211_RSNCAP_MFPC))
            fail |= IEEE80211_NODE_ASSOCFAIL_WPA_PROTO;
    }

    if (ic->ic_if.if_flags & IFF_DEBUG) {
        printf("%s: %c %s%c", ic->ic_if.if_xname, fail ? '-' : '+',
            ether_sprintf(ni->ni_bssid),
            fail & IEEE80211_NODE_ASSOCFAIL_BSSID ? '!' : ' ');
        printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan),
            fail & IEEE80211_NODE_ASSOCFAIL_CHAN ? '!' : ' ');
        printf(" %+4d", ni->ni_rssi);
        printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
            fail & IEEE80211_NODE_ASSOCFAIL_BASIC_RATE ? '!' : ' ');
        printf(" %4s%c",
            (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
            (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" :
            "????",
            fail & IEEE80211_NODE_ASSOCFAIL_IBSS ? '!' : ' ');
        printf(" %7s%c ",
            (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ?
            "privacy" : "no",
            fail & IEEE80211_NODE_ASSOCFAIL_PRIVACY ? '!' : ' ');
        printf(" %3s%c ",
            (ic->ic_flags & IEEE80211_F_RSNON) ?
            "rsn" : "no",
            fail & IEEE80211_NODE_ASSOCFAIL_WPA_PROTO ? '!' : ' ');
        ieee80211_print_essid(ni->ni_essid, ni->ni_esslen);
        printf("%s\n",
            fail & IEEE80211_NODE_ASSOCFAIL_ESSID ? "!" : "");
    }

    /* We don't care about unrelated networks during background scans. */
    if (bgscan) {
        if ((fail & IEEE80211_NODE_ASSOCFAIL_ESSID) == 0)
            ni->ni_assoc_fail = fail;
    } else
        ni->ni_assoc_fail = fail;
    if ((fail & IEEE80211_NODE_ASSOCFAIL_ESSID) == 0)
        ic->ic_bss->ni_assoc_fail = ni->ni_assoc_fail;

    return fail;
}

struct ieee80211_node_switch_bss_arg {
    u_int8_t cur_macaddr[IEEE80211_ADDR_LEN];
    u_int8_t sel_macaddr[IEEE80211_ADDR_LEN];
};

void
ieee80211_node_free_unref_cb(struct ieee80211_node *ni)
{
    free(ni->ni_unref_arg, M_DEVBUF, ni->ni_unref_arg_size);

    /* Guard against accidental reuse. */
    ni->ni_unref_cb = NULL;
    ni->ni_unref_arg = NULL;
    ni->ni_unref_arg_size = 0;
}

/* Implements ni->ni_unref_cb(). */
void
ieee80211_node_tx_stopped(struct ieee80211com *ic,
    struct ieee80211_node *ni)
{
    splassert(IPL_NET);

    if ((ic->ic_flags & IEEE80211_F_BGSCAN) == 0)
        return;

    /*
     * Install a callback which will switch us to the new AP once
     * the de-auth frame has been processed by hardware.
     * Pass on the existing ni->ni_unref_arg argument.
     */
    ic->ic_bss->ni_unref_cb = ieee80211_node_switch_bss;

    /*
     * All data frames queued to hardware have been flushed and
     * A-MPDU Tx has been stopped. We are now going to switch APs.
     * Queue a de-auth frame addressed at our current AP.
     */
    if (IEEE80211_SEND_MGMT(ic, ic->ic_bss,
        IEEE80211_FC0_SUBTYPE_DEAUTH,
        IEEE80211_REASON_AUTH_LEAVE) != 0) {
        ic->ic_flags &= ~IEEE80211_F_BGSCAN;
        ieee80211_node_free_unref_cb(ni);
        ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
        return;
    }

    /* F_BGSCAN flag gets cleared in ieee80211_node_join_bss(). */
}

/* Implements ni->ni_unref_cb(). */
void
ieee80211_node_tx_flushed(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    splassert(IPL_NET);

    if ((ic->ic_flags & IEEE80211_F_BGSCAN) == 0)
        return;

    /* All data frames queued to hardware have been flushed. */
    if (ic->ic_caps & IEEE80211_C_TX_AMPDU) {
        /*
         * Install a callback which will switch us to the
         * new AP once Tx agg sessions have been stopped,
         * which involves sending a DELBA frame.
         * Pass on the existing ni->ni_unref_arg argument.
         */
        ic->ic_bss->ni_unref_cb = ieee80211_node_tx_stopped;
        ieee80211_stop_ampdu_tx(ic, ic->ic_bss,
            IEEE80211_FC0_SUBTYPE_DEAUTH);
    } else
        ieee80211_node_tx_stopped(ic, ni);
}

/* Implements ni->ni_unref_cb(). */
void
ieee80211_node_switch_bss(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    struct ifnet *ifp = &ic->ic_if;
    struct ieee80211_node_switch_bss_arg *sba = (typeof sba)ni->ni_unref_arg;
    struct ieee80211_node *curbs, *selbs;

    splassert(IPL_NET);

    if ((ic->ic_flags & IEEE80211_F_BGSCAN) == 0)
        return;

    ic->ic_xflags &= ~IEEE80211_F_TX_MGMT_ONLY;

    selbs = ieee80211_find_node(ic, sba->sel_macaddr);
    if (selbs == NULL) {
        ieee80211_node_free_unref_cb(ni);
        ic->ic_flags &= ~IEEE80211_F_BGSCAN;
        ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
        return;
    }

    curbs = ieee80211_find_node(ic, sba->cur_macaddr);
    if (curbs == NULL) {
        ieee80211_node_free_unref_cb(ni);
        ic->ic_flags &= ~IEEE80211_F_BGSCAN;
        ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
        return;
    }

    if (ifp->if_flags & IFF_DEBUG) {
        printf("%s: roaming from %s chan %d ",
            ifp->if_xname, ether_sprintf(curbs->ni_macaddr),
            ieee80211_chan2ieee(ic, curbs->ni_chan));
        printf("to %s chan %d\n", ether_sprintf(selbs->ni_macaddr),
            ieee80211_chan2ieee(ic, selbs->ni_chan));
    }
    ieee80211_node_newstate(curbs, IEEE80211_STA_CACHE);
    /*
     * ieee80211_node_join_bss() frees arg and ic->ic_bss via
     * ic->ic_node_copy() in ieee80211_node_cleanup().
     */
    ieee80211_node_join_bss(ic, selbs);
}

void
ieee80211_node_join_bss(struct ieee80211com *ic, struct ieee80211_node *selbs)
{
    enum ieee80211_phymode mode;
    struct ieee80211_node *ni;
    uint32_t assoc_fail = 0;

    /* Reinitialize media mode and channels if needed. */
    mode = ieee80211_chan2mode(ic, selbs->ni_chan);
    if (mode != ic->ic_curmode)
        ieee80211_setmode(ic, mode);

    /* Keep recorded association failures for this BSS/ESS intact. */
    if (IEEE80211_ADDR_EQ(ic->ic_bss->ni_macaddr, selbs->ni_macaddr) ||
        (ic->ic_des_esslen > 0 && ic->ic_des_esslen == selbs->ni_esslen &&
        memcmp(ic->ic_des_essid, selbs->ni_essid, selbs->ni_esslen) == 0))
        assoc_fail = ic->ic_bss->ni_assoc_fail;

    (*ic->ic_node_copy)(ic, ic->ic_bss, selbs);
    ni = ic->ic_bss;
    ni->ni_assoc_fail |= assoc_fail;

    ic->ic_curmode = ieee80211_chan2mode(ic, ni->ni_chan);

    /* Make sure we send valid rates in an association request. */
    if (ic->ic_opmode == IEEE80211_M_STA)
        ieee80211_fix_rate(ic, ni,
            IEEE80211_F_DOSORT | IEEE80211_F_DOFRATE |
            IEEE80211_F_DONEGO | IEEE80211_F_DODEL);

    if (ic->ic_flags & IEEE80211_F_RSNON)
        ieee80211_choose_rsnparams(ic);
    else if (ic->ic_flags & IEEE80211_F_WEPON)
        ni->ni_rsncipher = IEEE80211_CIPHER_USEGROUP;

    ieee80211_node_newstate(selbs, IEEE80211_STA_BSS);
#ifndef IEEE80211_STA_ONLY
    if (ic->ic_opmode == IEEE80211_M_IBSS) {
        ieee80211_fix_rate(ic, ni, IEEE80211_F_DOFRATE |
            IEEE80211_F_DONEGO | IEEE80211_F_DODEL);
        if (ni->ni_rates.rs_nrates == 0) {
            ieee80211_new_state(ic, IEEE80211_S_SCAN, -1);
            return;
        }
        ieee80211_new_state(ic, IEEE80211_S_RUN, -1);
    } else
#endif
    {
        int bgscan = ((ic->ic_flags & IEEE80211_F_BGSCAN) &&
            ic->ic_opmode == IEEE80211_M_STA &&
            ic->ic_state == IEEE80211_S_RUN);
        int auth_next = (ic->ic_opmode == IEEE80211_M_STA &&
            ic->ic_state == IEEE80211_S_AUTH);
        int mgt = -1;

        timeout_del(&ic->ic_bgscan_timeout);
        ic->ic_flags &= ~IEEE80211_F_BGSCAN;

        /*
         * After a background scan, we have now switched APs.
         * Pretend we were just de-authed, which makes
         * ieee80211_new_state() try to re-auth and thus send
         * an AUTH frame to our newly selected AP.
         */
        if (bgscan)
            mgt = IEEE80211_FC0_SUBTYPE_DEAUTH;
        /*
         * If we are trying another AP after the previous one
         * failed (state transition AUTH->AUTH), ensure that
         * ieee80211_new_state() tries to send another auth frame.
         */
        else if (auth_next)
            mgt = IEEE80211_FC0_SUBTYPE_AUTH;

        ieee80211_new_state(ic, IEEE80211_S_AUTH, mgt);
    }
}

struct ieee80211_node *
ieee80211_node_choose_bss(struct ieee80211com *ic, int bgscan,
    struct ieee80211_node **curbs)
{
    struct ieee80211_node *ni, *nextbs, *selbs = NULL,
        *selbs2 = NULL, *selbs5 = NULL;
    uint8_t min_5ghz_rssi;

    ni = RBT_MIN(ieee80211_tree, &ic->ic_tree);

    for (; ni != NULL; ni = nextbs) {
        nextbs = RBT_NEXT(ieee80211_tree, ni);
        if (ni->ni_fails) {
            /*
             * The configuration of the access points may change
             * during my scan.  So delete the entry for the AP
             * and retry to associate if there is another beacon.
             */
            if (ni->ni_fails++ > 2)
                ieee80211_free_node(ic, ni);
            continue;
        }

        if (curbs && ieee80211_node_cmp(ic->ic_bss, ni) == 0)
            *curbs = ni;

        if (ieee80211_match_bss(ic, ni, bgscan) != 0)
            continue;

        if (ic->ic_caps & IEEE80211_C_SCANALLBAND) {
            if (IEEE80211_IS_CHAN_2GHZ(ni->ni_chan) &&
                (selbs2 == NULL || ni->ni_rssi > selbs2->ni_rssi))
                selbs2 = ni;
            else if (IEEE80211_IS_CHAN_5GHZ(ni->ni_chan) &&
                (selbs5 == NULL || ni->ni_rssi > selbs5->ni_rssi))
                selbs5 = ni;
        } else if (selbs == NULL || ni->ni_rssi > selbs->ni_rssi)
            selbs = ni;
    }

    if (ic->ic_max_rssi)
        min_5ghz_rssi = IEEE80211_RSSI_THRES_RATIO_5GHZ;
    else
        min_5ghz_rssi = (uint8_t)IEEE80211_RSSI_THRES_5GHZ;

    /*
     * Prefer a 5Ghz AP even if its RSSI is weaker than the best 2Ghz AP
     * (as long as it meets the minimum RSSI threshold) since the 5Ghz band
     * is usually less saturated.
     */
    if (selbs5 && (*ic->ic_node_checkrssi)(ic, selbs5))
        selbs = selbs5;
    else if (selbs5 && selbs2)
        selbs = (selbs5->ni_rssi >= selbs2->ni_rssi ? selbs5 : selbs2);
    else if (selbs2)
        selbs = selbs2;
    else if (selbs5)
        selbs = selbs5;

    return selbs;
}

/*
 * Complete a scan of potential channels.
 */
void
ieee80211_end_scan(struct ifnet *ifp)
{
    struct ieee80211com *ic = (typeof ic)ifp;
    struct ieee80211_node *ni, *selbs = NULL, *curbs = NULL;
    int bgscan = ((ic->ic_flags & IEEE80211_F_BGSCAN) &&
        ic->ic_opmode == IEEE80211_M_STA &&
        ic->ic_state == IEEE80211_S_RUN);

    if (ifp->if_flags & IFF_DEBUG)
        printf("%s: end %s scan\n", ifp->if_xname,
            bgscan ? "background" :
            ((ic->ic_flags & IEEE80211_F_ASCAN) ?
            "active" : "passive"));

    if (ic->ic_scan_count)
        ic->ic_flags &= ~IEEE80211_F_ASCAN;

    if (ic->ic_opmode == IEEE80211_M_STA)
        ieee80211_clean_inactive_nodes(ic, IEEE80211_INACT_SCAN);

    ni = RBT_MIN(ieee80211_tree, &ic->ic_tree);

#ifndef IEEE80211_STA_ONLY
    if (ic->ic_opmode == IEEE80211_M_HOSTAP) {
        /* XXX off stack? */
        u_char occupied[howmany(IEEE80211_CHAN_MAX, NBBY)];
        int i, fail;

        /*
         * The passive scan to look for existing AP's completed,
         * select a channel to camp on.  Identify the channels
         * that already have one or more AP's and try to locate
         * an unoccupied one.  If that fails, pick a random
         * channel from the active set.
         */
        memset(occupied, 0, sizeof(occupied));
        RBT_FOREACH(ni, ieee80211_tree, &ic->ic_tree)
            setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan));
        for (i = 0; i < IEEE80211_CHAN_MAX; i++)
            if (isset(ic->ic_chan_active, i) && isclr(occupied, i))
                break;
        if (i == IEEE80211_CHAN_MAX) {
            fail = arc4random() & 3;    /* random 0-3 */
            for (i = 0; i < IEEE80211_CHAN_MAX; i++)
                if (isset(ic->ic_chan_active, i) && fail-- == 0)
                    break;
        }
        ieee80211_create_ibss(ic, &ic->ic_channels[i]);
        return;
    }
#endif
    if (ni == NULL) {
        DPRINTF(("no scan candidate\n"));
 notfound:

#ifndef IEEE80211_STA_ONLY
        if (ic->ic_opmode == IEEE80211_M_IBSS &&
            (ic->ic_flags & IEEE80211_F_IBSSON) &&
            ic->ic_des_esslen != 0) {
            ieee80211_create_ibss(ic, ic->ic_ibss_chan);
            return;
        }
#endif
        /*
         * Reset the list of channels to scan and scan the next mode
         * if nothing has been found.
         * If the device scans all bands in one fell swoop, return
         * current scan results to userspace regardless of mode.
         * This will loop forever until an access point is found.
         */
        ieee80211_reset_scan(ifp);
        if (ieee80211_next_mode(ifp) == IEEE80211_MODE_AUTO ||
            (ic->ic_caps & IEEE80211_C_SCANALLBAND))
            ic->ic_scan_count++;

        ieee80211_next_scan(ifp);
        return;
    }

    /* Possibly switch which ssid we are associated with */
    if (!bgscan && ic->ic_opmode == IEEE80211_M_STA)
        ieee80211_switch_ess(ic);

    selbs = ieee80211_node_choose_bss(ic, bgscan, &curbs);
    if (bgscan) {
        struct ieee80211_node_switch_bss_arg *arg;

        /* AP disappeared? Should not happen. */
        if (selbs == NULL || curbs == NULL) {
            ic->ic_flags &= ~IEEE80211_F_BGSCAN;
            goto notfound;
        }

        /*
         * After a background scan we might end up choosing the
         * same AP again. Or the newly selected AP's RSSI level
         * might be low enough to trigger another background scan.
         * Do not change ic->ic_bss in these cases and make
         * background scans less frequent.
         */
        if (selbs == curbs || !(*ic->ic_node_checkrssi)(ic, selbs)) {
            if (ic->ic_bgscan_fail < IEEE80211_BGSCAN_FAIL_MAX) {
                if (ic->ic_bgscan_fail <= 0)
                    ic->ic_bgscan_fail = 1;
                else
                    ic->ic_bgscan_fail *= 2;
            }
            ic->ic_flags &= ~IEEE80211_F_BGSCAN;

            /*
             * HT is negotiated during association so we must use
             * ic_bss to check HT. The nodes tree was re-populated
             * during background scan and therefore selbs and curbs
             * may not carry HT information.
             */
            ni = ic->ic_bss;
            if (ni->ni_flags & IEEE80211_NODE_VHT)
                ieee80211_setmode(ic, IEEE80211_MODE_11AC);
            else if (ni->ni_flags & IEEE80211_NODE_HT)
                ieee80211_setmode(ic, IEEE80211_MODE_11N);
            else
                ieee80211_setmode(ic,
                    ieee80211_chan2mode(ic, ni->ni_chan));
            return;
        }
    
        arg = (typeof arg)malloc(sizeof(*arg), M_DEVBUF, M_NOWAIT | M_ZERO);
        if (arg == NULL) {
            ic->ic_flags &= ~IEEE80211_F_BGSCAN;
            return;
        }

        ic->ic_bgscan_fail = 0;

        /* Prevent dispatch of additional data frames to hardware. */
        ic->ic_xflags |= IEEE80211_F_TX_MGMT_ONLY;

        IEEE80211_ADDR_COPY(arg->cur_macaddr, curbs->ni_macaddr);
        IEEE80211_ADDR_COPY(arg->sel_macaddr, selbs->ni_macaddr);

        if (ic->ic_bgscan_done) {
            /*
             * The driver will flush its queues and allow roaming
             * to proceed once queues have been flushed.
             * On failure the driver will move back to SCAN state.
             */
            ic->ic_bgscan_done(ic, arg, sizeof(*arg));
            return;
        }

        /*
         * Install a callback which will switch us to the new AP once
         * all dispatched frames have been processed by hardware.
         */
        ic->ic_bss->ni_unref_arg = arg;
        ic->ic_bss->ni_unref_arg_size = sizeof(*arg);
        if (ic->ic_bss->ni_refcnt > 0)
            ic->ic_bss->ni_unref_cb = ieee80211_node_tx_flushed;
        else
            ieee80211_node_tx_flushed(ic, ni);
        /* F_BGSCAN flag gets cleared in ieee80211_node_join_bss(). */
        return;
    } else if (selbs == NULL)
        goto notfound;

    ieee80211_node_join_bss(ic, selbs);
}

/*
 * Autoselect the best RSN parameters (protocol, AKMP, pairwise cipher...)
 * that are supported by both peers (STA mode only).
 */
void
ieee80211_choose_rsnparams(struct ieee80211com *ic)
{
    struct ieee80211_node *ni = ic->ic_bss;
    struct ieee80211_pmk *pmk;

    /* filter out unsupported protocol versions */
    ni->ni_rsnprotos &= ic->ic_rsnprotos;
    /* prefer RSN (aka WPA2) over WPA */
    if (ni->ni_rsnprotos & IEEE80211_PROTO_RSN)
        ni->ni_rsnprotos = IEEE80211_PROTO_RSN;
    else
        ni->ni_rsnprotos = IEEE80211_PROTO_WPA;

    /* filter out unsupported AKMPs */
    ni->ni_rsnakms &= ic->ic_rsnakms;
    /* prefer SHA-256 based AKMPs */
    if ((ic->ic_flags & IEEE80211_F_PSK) && (ni->ni_rsnakms &
        (IEEE80211_AKM_PSK | IEEE80211_AKM_SHA256_PSK))) {
        /* AP supports PSK AKMP and a PSK is configured */
        if (ni->ni_rsnakms & IEEE80211_AKM_SHA256_PSK)
            ni->ni_rsnakms = IEEE80211_AKM_SHA256_PSK;
        else
            ni->ni_rsnakms = IEEE80211_AKM_PSK;
    } else {
        if (ni->ni_rsnakms & IEEE80211_AKM_SHA256_8021X)
            ni->ni_rsnakms = IEEE80211_AKM_SHA256_8021X;
        else
            ni->ni_rsnakms = IEEE80211_AKM_8021X;
        /* check if we have a cached PMK for this AP */
        if (ni->ni_rsnprotos == IEEE80211_PROTO_RSN &&
            (pmk = ieee80211_pmksa_find(ic, ni, NULL)) != NULL) {
            memcpy(ni->ni_pmkid, pmk->pmk_pmkid,
                IEEE80211_PMKID_LEN);
            ni->ni_flags |= IEEE80211_NODE_PMKID;
        }
    }

    /* filter out unsupported pairwise ciphers */
    ni->ni_rsnciphers &= ic->ic_rsnciphers;
    /* prefer CCMP over TKIP */
    if (ni->ni_rsnciphers & IEEE80211_CIPHER_CCMP)
        ni->ni_rsnciphers = IEEE80211_CIPHER_CCMP;
    else
        ni->ni_rsnciphers = IEEE80211_CIPHER_TKIP;
    ni->ni_rsncipher = (typeof ni->ni_rsncipher)ni->ni_rsnciphers;

    /* use MFP if we both support it */
    if ((ic->ic_caps & IEEE80211_C_MFP) &&
        (ni->ni_rsncaps & IEEE80211_RSNCAP_MFPC))
        ni->ni_flags |= IEEE80211_NODE_MFP;
}

int
ieee80211_get_rate(struct ieee80211com *ic)
{
    u_int8_t (*rates)[IEEE80211_RATE_MAXSIZE];
    int rate;

    rates = &ic->ic_bss->ni_rates.rs_rates;

    if (ic->ic_fixed_rate != -1)
        rate = (*rates)[ic->ic_fixed_rate];
    else if (ic->ic_state == IEEE80211_S_RUN)
        rate = (*rates)[ic->ic_bss->ni_txrate];
    else
        rate = 0;

    return rate & IEEE80211_RATE_VAL;
}

struct ieee80211_node *
ieee80211_node_alloc(struct ieee80211com *ic)
{
    return (struct ieee80211_node *)malloc(sizeof(struct ieee80211_node), M_DEVBUF,
        M_NOWAIT | M_ZERO);
}

void
ieee80211_node_cleanup(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    if (ni->ni_rsnie != NULL) {
        free(ni->ni_rsnie, M_DEVBUF, 2 + ni->ni_rsnie[1]);
        ni->ni_rsnie = NULL;
    }
    if (ni->ni_countryie != NULL) {
        free(ni->ni_countryie, M_DEVBUF, 2 + ni->ni_countryie[1]);
        ni->ni_countryie = NULL;
    }
    if (ni->ni_ie != NULL && ni->ni_ie_len > 0) {
        free(ni->ni_ie, M_DEVBUF, ni->ni_ie_len);
        ni->ni_ie = NULL;
        ni->ni_ie_len = 0;
    }
    ieee80211_ba_del(ni);
#ifndef IEEE80211_STA_ONLY
    mq_purge(&ni->ni_savedq);
#endif
    ieee80211_node_free_unref_cb(ni);
}

void
ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    ieee80211_node_cleanup(ic, ni);
    free(ni, M_DEVBUF, 0);
}

void
ieee80211_node_copy(struct ieee80211com *ic,
    struct ieee80211_node *dst, const struct ieee80211_node *src)
{
    ieee80211_node_cleanup(ic, dst);
    *dst = *src;
    dst->ni_rsnie = NULL;
    if (src->ni_rsnie != NULL)
        ieee80211_save_ie(src->ni_rsnie, &dst->ni_rsnie);
    dst->ni_countryie = NULL;
    if (src->ni_countryie != NULL)
        ieee80211_save_ie(src->ni_countryie, &dst->ni_countryie);
    dst->ni_ie = NULL;
    dst->ni_ie_len = 0;
    if (src->ni_ie != NULL && src->ni_ie_len > 0) {
        ieee80211_save_ie(src->ni_ie, src->ni_ie_len, &dst->ni_ie, &dst->ni_ie_len);
    }
    ieee80211_node_set_timeouts(dst);
#ifndef IEEE80211_STA_ONLY
    mq_init(&dst->ni_savedq, IEEE80211_PS_MAX_QUEUE, IPL_NET);
#endif
}

u_int8_t
ieee80211_node_getrssi(struct ieee80211com *ic,
    const struct ieee80211_node *ni)
{
    return ni->ni_rssi;
}

int
ieee80211_node_checkrssi(struct ieee80211com *ic,
    const struct ieee80211_node *ni)
{
    uint8_t thres;

    if (ni->ni_chan == IEEE80211_CHAN_ANYC)
        return 0;

    if (ic->ic_max_rssi) {
        thres = (IEEE80211_IS_CHAN_2GHZ(ni->ni_chan)) ?
            IEEE80211_RSSI_THRES_RATIO_2GHZ :
            IEEE80211_RSSI_THRES_RATIO_5GHZ;
        return ((ni->ni_rssi * 100) / ic->ic_max_rssi >= thres);
    }

    thres = (IEEE80211_IS_CHAN_2GHZ(ni->ni_chan)) ?
        IEEE80211_RSSI_THRES_2GHZ :
        IEEE80211_RSSI_THRES_5GHZ;
    return (ni->ni_rssi >= (u_int8_t)thres);
}

void
ieee80211_node_set_timeouts(struct ieee80211_node *ni)
{
    int i;

#ifndef IEEE80211_STA_ONLY
    timeout_set(&ni->ni_eapol_to, ieee80211_eapol_timeout, ni);
    timeout_set(&ni->ni_sa_query_to, ieee80211_sa_query_timeout, ni);
#endif
    timeout_set(&ni->ni_addba_req_to[EDCA_AC_BE],
        ieee80211_node_addba_request_ac_be_to, ni);
    timeout_set(&ni->ni_addba_req_to[EDCA_AC_BK],
        ieee80211_node_addba_request_ac_bk_to, ni);
    timeout_set(&ni->ni_addba_req_to[EDCA_AC_VI],
        ieee80211_node_addba_request_ac_vi_to, ni);
    timeout_set(&ni->ni_addba_req_to[EDCA_AC_VO],
        ieee80211_node_addba_request_ac_vo_to, ni);
    for (i = 0; i < nitems(ni->ni_addba_req_intval); i++)
        ni->ni_addba_req_intval[i] = 1;
}

void
ieee80211_setup_node(struct ieee80211com *ic,
    struct ieee80211_node *ni, const u_int8_t *macaddr)
{
    int i, s;

    DPRINTF(("%s\n", ether_sprintf((u_int8_t *)macaddr)));
    IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr);
    ieee80211_node_newstate(ni, IEEE80211_STA_CACHE);

    ni->ni_ic = ic;    /* back-pointer */
    /* Initialize cached last sequence numbers with invalid values. */
    ni->ni_rxseq = 0xffffU;
    for (i=0; i < IEEE80211_NUM_TID; ++i)
        ni->ni_qos_rxseqs[i] = 0xffffU;
#ifndef IEEE80211_STA_ONLY
    mq_init(&ni->ni_savedq, IEEE80211_PS_MAX_QUEUE, IPL_NET);
#endif
    ieee80211_node_set_timeouts(ni);

    s = splnet();
    RBT_INSERT(ieee80211_tree, &ic->ic_tree, ni);
    ic->ic_nnodes++;
    splx(s);
}

struct ieee80211_node *
ieee80211_alloc_node(struct ieee80211com *ic, const u_int8_t *macaddr)
{
    struct ieee80211_node *ni = ieee80211_alloc_node_helper(ic);
    if (ni != NULL)
        ieee80211_setup_node(ic, ni, macaddr);
    else
        ic->ic_stats.is_rx_nodealloc++;
    return ni;
}

struct ieee80211_node *
ieee80211_dup_bss(struct ieee80211com *ic, const u_int8_t *macaddr)
{
    struct ieee80211_node *ni = ieee80211_alloc_node_helper(ic);
    if (ni != NULL) {
        ieee80211_setup_node(ic, ni, macaddr);
        /*
         * Inherit from ic_bss.
         */
        IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid);
        ni->ni_chan = ic->ic_bss->ni_chan;
    } else
        ic->ic_stats.is_rx_nodealloc++;
    return ni;
}

struct ieee80211_node *
ieee80211_find_node(struct ieee80211com *ic, const u_int8_t *macaddr)
{
    struct ieee80211_node *ni;
    int cmp;

    /* similar to RBT_FIND except we compare keys, not nodes */
    ni = RBT_ROOT(ieee80211_tree, &ic->ic_tree);
    while (ni != NULL) {
        cmp = memcmp(macaddr, ni->ni_macaddr, IEEE80211_ADDR_LEN);
        if (cmp < 0)
            ni = RBT_LEFT(ieee80211_tree, ni);
        else if (cmp > 0)
            ni = RBT_RIGHT(ieee80211_tree, ni);
        else
            break;
    }
    return ni;
}

/*
 * Return a reference to the appropriate node for sending
 * a data frame.  This handles node discovery in adhoc networks.
 *
 * Drivers will call this, so increase the reference count before
 * returning the node.
 */
struct ieee80211_node *
ieee80211_find_txnode(struct ieee80211com *ic, const u_int8_t *macaddr)
{
#ifndef IEEE80211_STA_ONLY
    struct ieee80211_node *ni;
    int s;
#endif

    /*
     * The destination address should be in the node table
     * unless we are operating in station mode or this is a
     * multicast/broadcast frame.
     */
    if (ic->ic_opmode == IEEE80211_M_STA || IEEE80211_IS_MULTICAST(macaddr))
        return ieee80211_ref_node(ic->ic_bss);

#ifndef IEEE80211_STA_ONLY
    s = splnet();
    ni = ieee80211_find_node(ic, macaddr);
    splx(s);
    if (ni == NULL) {
        if (ic->ic_opmode != IEEE80211_M_IBSS &&
            ic->ic_opmode != IEEE80211_M_AHDEMO)
            return NULL;

        /*
         * Fake up a node; this handles node discovery in
         * adhoc mode.  Note that for the driver's benefit
         * we treat this like an association so the driver
         * has an opportunity to setup its private state.
         *
         * XXX need better way to handle this; issue probe
         *     request so we can deduce rate set, etc.
         */
        if ((ni = ieee80211_dup_bss(ic, macaddr)) == NULL)
            return NULL;
        /* XXX no rate negotiation; just dup */
        ni->ni_rates = ic->ic_bss->ni_rates;
        ni->ni_txrate = 0;
        if (ic->ic_newassoc)
            (*ic->ic_newassoc)(ic, ni, 1);
    }
    return ieee80211_ref_node(ni);
#else
    return NULL;    /* can't get there */
#endif    /* IEEE80211_STA_ONLY */
}

/*
 * It is usually desirable to process a Rx packet using its sender's
 * node-record instead of the BSS record.
 *
 * - AP mode: keep a node-record for every authenticated/associated
 *   station *in the BSS*. For future use, we also track neighboring
 *   APs, since they might belong to the same ESS.  APs in the same
 *   ESS may bridge packets to each other, forming a Wireless
 *   Distribution System (WDS).
 *
 * - IBSS mode: keep a node-record for every station *in the BSS*.
 *   Also track neighboring stations by their beacons/probe responses.
 *
 * - monitor mode: keep a node-record for every sender, regardless
 *   of BSS.
 *
 * - STA mode: the only available node-record is the BSS record,
 *   ic->ic_bss.
 *
 * Of all the 802.11 Control packets, only the node-records for
 * RTS packets node-record can be looked up.
 *
 * Return non-zero if the packet's node-record is kept, zero
 * otherwise.
 */
static __inline int
ieee80211_needs_rxnode(struct ieee80211com *ic,
    const struct ieee80211_frame *wh, const u_int8_t **bssid)
{
    int monitor, rc = 0;

    monitor = (ic->ic_opmode == IEEE80211_M_MONITOR);

    *bssid = NULL;

    switch (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) {
    case IEEE80211_FC0_TYPE_CTL:
        if (!monitor)
            break;
        return (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) ==
            IEEE80211_FC0_SUBTYPE_RTS;
    case IEEE80211_FC0_TYPE_MGT:
        *bssid = wh->i_addr3;
        switch (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) {
        case IEEE80211_FC0_SUBTYPE_BEACON:
        case IEEE80211_FC0_SUBTYPE_PROBE_RESP:
            break;
        default:
#ifndef IEEE80211_STA_ONLY
            if (ic->ic_opmode == IEEE80211_M_STA)
                break;
            rc = IEEE80211_ADDR_EQ(*bssid, ic->ic_bss->ni_bssid) ||
                 IEEE80211_ADDR_EQ(*bssid, etherbroadcastaddr);
#endif
            break;
        }
        break;
    case IEEE80211_FC0_TYPE_DATA:
        switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) {
        case IEEE80211_FC1_DIR_NODS:
            *bssid = wh->i_addr3;
#ifndef IEEE80211_STA_ONLY
            if (ic->ic_opmode == IEEE80211_M_IBSS ||
                ic->ic_opmode == IEEE80211_M_AHDEMO)
                rc = IEEE80211_ADDR_EQ(*bssid,
                    ic->ic_bss->ni_bssid);
#endif
            break;
        case IEEE80211_FC1_DIR_TODS:
            *bssid = wh->i_addr1;
#ifndef IEEE80211_STA_ONLY
            if (ic->ic_opmode == IEEE80211_M_HOSTAP)
                rc = IEEE80211_ADDR_EQ(*bssid,
                    ic->ic_bss->ni_bssid);
#endif
            break;
        case IEEE80211_FC1_DIR_FROMDS:
        case IEEE80211_FC1_DIR_DSTODS:
            *bssid = wh->i_addr2;
#ifndef IEEE80211_STA_ONLY
            rc = (ic->ic_opmode == IEEE80211_M_HOSTAP);
#endif
            break;
        }
        break;
    }
    return monitor || rc;
}

/*
 * Drivers call this, so increase the reference count before returning
 * the node.
 */
struct ieee80211_node *
ieee80211_find_rxnode(struct ieee80211com *ic,
    const struct ieee80211_frame *wh)
{
    static const u_int8_t zero[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
    struct ieee80211_node *ni;
    const u_int8_t *bssid;
    int s;

    if (!ieee80211_needs_rxnode(ic, wh, &bssid))
        return ieee80211_ref_node(ic->ic_bss);

    s = splnet();
    ni = ieee80211_find_node(ic, wh->i_addr2);
    splx(s);

    if (ni != NULL)
        return ieee80211_ref_node(ni);
#ifndef IEEE80211_STA_ONLY
    if (ic->ic_opmode == IEEE80211_M_HOSTAP)
        return ieee80211_ref_node(ic->ic_bss);
#endif
    /* XXX see remarks in ieee80211_find_txnode */
    /* XXX no rate negotiation; just dup */
    if ((ni = ieee80211_dup_bss(ic, wh->i_addr2)) == NULL)
        return ieee80211_ref_node(ic->ic_bss);

    IEEE80211_ADDR_COPY(ni->ni_bssid, (bssid != NULL) ? bssid : zero);

    ni->ni_rates = ic->ic_bss->ni_rates;
    ni->ni_txrate = 0;
    if (ic->ic_newassoc)
        (*ic->ic_newassoc)(ic, ni, 1);

    DPRINTF(("faked-up node %p for %s\n", ni,
        ether_sprintf((u_int8_t *)wh->i_addr2)));

    return ieee80211_ref_node(ni);
}

void
ieee80211_node_tx_ba_clear(struct ieee80211_node *ni, int tid)
{
    struct ieee80211_tx_ba *ba = &ni->ni_tx_ba[tid];

    if (ba->ba_state != IEEE80211_BA_INIT) {
        if (timeout_pending(&ba->ba_to))
            timeout_del(&ba->ba_to);
        ba->ba_state = IEEE80211_BA_INIT;
    }
}

void
ieee80211_ba_del(struct ieee80211_node *ni)
{
    int tid;

    for (tid = 0; tid < nitems(ni->ni_rx_ba); tid++) {
        struct ieee80211_rx_ba *ba = &ni->ni_rx_ba[tid];
        if (ba->ba_state != IEEE80211_BA_INIT) {
            if (timeout_pending(&ba->ba_to))
                timeout_del(&ba->ba_to);
            if (timeout_pending(&ba->ba_gap_to))
                timeout_del(&ba->ba_gap_to);
            ba->ba_state = IEEE80211_BA_INIT;
        }
    }

    for (tid = 0; tid < nitems(ni->ni_tx_ba); tid++)
        ieee80211_node_tx_ba_clear(ni, tid);

    timeout_del(&ni->ni_addba_req_to[EDCA_AC_BE]);
    timeout_del(&ni->ni_addba_req_to[EDCA_AC_BK]);
    timeout_del(&ni->ni_addba_req_to[EDCA_AC_VI]);
    timeout_del(&ni->ni_addba_req_to[EDCA_AC_VO]);
}

void
ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    if (ni == ic->ic_bss)
        panic("freeing bss node");

    splassert(IPL_NET);

    DPRINTF(("%s\n", ether_sprintf(ni->ni_macaddr)));
#ifndef IEEE80211_STA_ONLY
    timeout_del(&ni->ni_eapol_to);
    timeout_del(&ni->ni_sa_query_to);
    IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap);
#endif
    ieee80211_ba_del(ni);
    RBT_REMOVE(ieee80211_tree, &ic->ic_tree, ni);
    ic->ic_nnodes--;
#ifndef IEEE80211_STA_ONLY
    if (mq_purge(&ni->ni_savedq) > 0) {
        if (ic->ic_set_tim != NULL)
            (*ic->ic_set_tim)(ic, ni->ni_associd, 0);
    }
#endif
    (*ic->ic_node_free)(ic, ni);
    /* TBD indicate to drivers that a new node can be allocated */
}

void
ieee80211_release_node(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    int s;
    void (*ni_unref_cb)(struct ieee80211com *, struct ieee80211_node *);

    DPRINTF(("%s refcnt %u\n", ether_sprintf(ni->ni_macaddr),
        ni->ni_refcnt));
    s = splnet();
    if (ieee80211_node_decref(ni) == 0) {
        if (ni->ni_unref_cb) {
            /* The callback may set ni->ni_unref_cb again. */
            ni_unref_cb = ni->ni_unref_cb;
            ni->ni_unref_cb = NULL;
             /* Freed by callback if necessary: */
            (*ni_unref_cb)(ic, ni);
        }
            if (ni->ni_state == IEEE80211_STA_COLLECT)
            ieee80211_free_node(ic, ni);
    }
    splx(s);
}

void
ieee80211_free_allnodes(struct ieee80211com *ic, int clear_ic_bss)
{
    struct ieee80211_node *ni;
    int s;

    DPRINTF(("freeing all nodes\n"));
    s = splnet();
    while ((ni = RBT_MIN(ieee80211_tree, &ic->ic_tree)) != NULL)
        ieee80211_free_node(ic, ni);
    splx(s);

    if (clear_ic_bss && ic->ic_bss != NULL)
        ieee80211_node_cleanup(ic, ic->ic_bss);
}

void
ieee80211_clean_cached(struct ieee80211com *ic)
{
    struct ieee80211_node *ni, *next_ni;
    int s;

    s = splnet();
    for (ni = RBT_MIN(ieee80211_tree, &ic->ic_tree);
        ni != NULL; ni = next_ni) {
        next_ni = RBT_NEXT(ieee80211_tree, ni);
        if (ni->ni_state == IEEE80211_STA_CACHE)
            ieee80211_free_node(ic, ni);
    }
    splx(s);
}
/*
 * Timeout inactive nodes.
 *
 * If called because of a cache timeout, which happens only in hostap and ibss
 * modes, clean all inactive cached or authenticated nodes but don't de-auth
 * any associated nodes. Also update HT protection settings.
 *
 * Else, this function is called because a new node must be allocated but the
 * node cache is full. In this case, return as soon as a free slot was made
 * available. If acting as hostap, clean cached nodes regardless of their
 * recent activity and also allow de-authing of authenticated nodes older
 * than one cache wait interval, and de-authing of inactive associated nodes.
 */
void
ieee80211_clean_nodes(struct ieee80211com *ic, int cache_timeout)
{
    struct ieee80211_node *ni, *next_ni;
    u_int gen = ic->ic_scangen++;        /* NB: ok 'cuz single-threaded*/
    int s;
#ifndef IEEE80211_STA_ONLY
    int nnodes = 0, nonht = 0, nonhtassoc = 0;
    struct ifnet *ifp = &ic->ic_if;
    enum ieee80211_htprot htprot = IEEE80211_HTPROT_NONE;
    enum ieee80211_protmode protmode = IEEE80211_PROT_NONE;
#endif

    s = splnet();
    for (ni = RBT_MIN(ieee80211_tree, &ic->ic_tree);
        ni != NULL; ni = next_ni) {
        next_ni = RBT_NEXT(ieee80211_tree, ni);
        if (!cache_timeout && ic->ic_nnodes < ic->ic_max_nnodes)
            break;
        if (ni->ni_scangen == gen)    /* previously handled */
            continue;
#ifndef IEEE80211_STA_ONLY
        nnodes++;
        if ((ic->ic_flags & IEEE80211_F_HTON) && cache_timeout) {
            /*
             * Check if node supports 802.11n.
             * Only require HT capabilities IE for this check.
             * Nodes might never reveal their supported MCS to us
             * unless they go through a full association sequence.
             * ieee80211_node_supports_ht() could misclassify them.
             */
            if ((ni->ni_flags & IEEE80211_NODE_HTCAP) == 0) {
                nonht++;
                if (ni->ni_state == IEEE80211_STA_ASSOC)
                    nonhtassoc++;
            }
        }
#endif
        ni->ni_scangen = gen;
        if (ni->ni_refcnt > 0)
            continue;
#ifndef IEEE80211_STA_ONLY
        if ((ic->ic_opmode == IEEE80211_M_HOSTAP ||
            ic->ic_opmode == IEEE80211_M_IBSS) &&
            ic->ic_state == IEEE80211_S_RUN) {
            if (cache_timeout) {
                if (ni->ni_state != IEEE80211_STA_COLLECT &&
                    (ni->ni_state == IEEE80211_STA_ASSOC ||
                    ni->ni_inact < IEEE80211_INACT_MAX))
                    continue;
            } else {
                if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
                    ((ni->ni_state == IEEE80211_STA_ASSOC &&
                    ni->ni_inact < IEEE80211_INACT_MAX) ||
                    (ni->ni_state == IEEE80211_STA_AUTH &&
                     ni->ni_inact == 0)))
                        continue;

                if (ic->ic_opmode == IEEE80211_M_IBSS &&
                    ni->ni_state != IEEE80211_STA_COLLECT &&
                    ni->ni_state != IEEE80211_STA_CACHE &&
                    ni->ni_inact < IEEE80211_INACT_MAX)
                    continue;
            }
        }
        if (ifp->if_flags & IFF_DEBUG)
            printf("%s: station %s purged from node cache\n",
                ifp->if_xname, ether_sprintf(ni->ni_macaddr));
#endif
        /*
         * If we're hostap and the node is authenticated, send
         * a deauthentication frame. The node will be freed when
         * the driver calls ieee80211_release_node().
         */
#ifndef IEEE80211_STA_ONLY
        nnodes--;
        if ((ic->ic_flags & IEEE80211_F_HTON) && cache_timeout) {
            if ((ni->ni_flags & IEEE80211_NODE_HTCAP) == 0) {
                nonht--;
                if (ni->ni_state == IEEE80211_STA_ASSOC)
                    nonhtassoc--;
            }
        }
        if (ic->ic_opmode == IEEE80211_M_HOSTAP &&
            ni->ni_state >= IEEE80211_STA_AUTH &&
            ni->ni_state != IEEE80211_STA_COLLECT) {
            IEEE80211_SEND_MGMT(ic, ni,
                IEEE80211_FC0_SUBTYPE_DEAUTH,
                IEEE80211_REASON_AUTH_EXPIRE);
            ieee80211_node_leave(ic, ni);
        } else
#endif
            ieee80211_free_node(ic, ni);
        ic->ic_stats.is_node_timeout++;
    }

#ifndef IEEE80211_STA_ONLY
    if ((ic->ic_flags & IEEE80211_F_HTON) && cache_timeout) {
        uint16_t htop1 = ic->ic_bss->ni_htop1;

        /* Update HT protection settings. */
        if (nonht) {
            protmode = IEEE80211_PROT_CTSONLY;
            if (nonhtassoc)
                htprot = IEEE80211_HTPROT_NONHT_MIXED;
            else
                htprot = IEEE80211_HTPROT_NONMEMBER;
        }
        if ((htop1 & IEEE80211_HTOP1_PROT_MASK) != htprot) {
            htop1 &= ~IEEE80211_HTOP1_PROT_MASK;
            htop1 |= htprot;
            ic->ic_bss->ni_htop1 = htop1;
            ic->ic_protmode = protmode;
            if (ic->ic_updateprot)
                ic->ic_updateprot(ic);
        }
    }

    /*
     * During a cache timeout we iterate over all nodes.
     * Check for node leaks by comparing the actual number of cached
     * nodes with the ic_nnodes count, which is maintained while adding
     * and removing nodes from the cache.
     */
    if ((ifp->if_flags & IFF_DEBUG) && cache_timeout &&
        nnodes != ic->ic_nnodes)
        printf("%s: number of cached nodes is %d, expected %d,"
            "possible nodes leak\n", ifp->if_xname, nnodes,
            ic->ic_nnodes);
#endif
    splx(s);
}

void
ieee80211_clean_inactive_nodes(struct ieee80211com *ic, int inact_max)
{
    struct ieee80211_node *ni, *next_ni;
    u_int gen = ic->ic_scangen++;    /* NB: ok 'cuz single-threaded*/
    int s;

    s = splnet();
    for (ni = RBT_MIN(ieee80211_tree, &ic->ic_tree);
        ni != NULL; ni = next_ni) {
        next_ni = RBT_NEXT(ieee80211_tree, ni);
        if (ni->ni_scangen == gen)    /* previously handled */
            continue;
        ni->ni_scangen = gen;
        if (ni->ni_refcnt > 0 || ni->ni_inact < inact_max)
            continue;
        ieee80211_free_node(ic, ni);
        ic->ic_stats.is_node_timeout++;
    }

    splx(s);
}

void
ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f,
    void *arg)
{
    struct ieee80211_node *ni;
    int s;

    s = splnet();
    RBT_FOREACH(ni, ieee80211_tree, &ic->ic_tree)
        (*f)(arg, ni);
    splx(s);
}


/*
 * Install received HT caps information in the node's state block.
 */
void
ieee80211_setup_htcaps(struct ieee80211_node *ni, const uint8_t *data,
    uint8_t len)
{
    uint16_t rxrate;

    if (len != 26)
        return;

    ni->ni_htcaps = (data[0] | (data[1] << 8));
    ni->ni_ampdu_param = data[2];

    memcpy(ni->ni_rxmcs, &data[3], sizeof(ni->ni_rxmcs));
    /* clear reserved bits */
    clrbit(ni->ni_rxmcs, 77);
    clrbit(ni->ni_rxmcs, 78);
    clrbit(ni->ni_rxmcs, 79);

    /* Max MCS Rx rate in 1Mb/s units (0 means "not specified"). */
    rxrate = ((data[13] | (data[14]) << 8) & IEEE80211_MCS_RX_RATE_HIGH);
    if (rxrate < 1024)
        ni->ni_max_rxrate = rxrate;

    ni->ni_tx_mcs_set = data[15];
    ni->ni_htxcaps = (data[19] | (data[20] << 8));
    ni->ni_txbfcaps = (data[21] | (data[22] << 8) | (data[23] << 16) |
        (data[24] << 24));
    ni->ni_aselcaps = data[25];

    ni->ni_flags |= IEEE80211_NODE_HTCAP;
}

#ifndef IEEE80211_STA_ONLY
/*
 * Handle nodes switching from 11n into legacy modes.
 */
void
ieee80211_clear_htcaps(struct ieee80211_node *ni)
{
    ni->ni_htcaps = 0;
    ni->ni_ampdu_param = 0;
    memset(ni->ni_rxmcs, 0, sizeof(ni->ni_rxmcs));
    ni->ni_max_rxrate = 0;
    ni->ni_tx_mcs_set = 0;
    ni->ni_htxcaps = 0;
    ni->ni_txbfcaps = 0;
    ni->ni_aselcaps = 0;

    ni->ni_flags &= ~(IEEE80211_NODE_HT | IEEE80211_NODE_HT_SGI20 |
        IEEE80211_NODE_HT_SGI40 | IEEE80211_NODE_HTCAP);

}
#endif

int
ieee80211_40mhz_valid_secondary_above(uint8_t primary_chan)
{
    static const uint8_t valid_secondary_chan[] = {
        5, 6, 7, 8, 9, 10, 11, 12, 13,
        40, 48, 56, 64, 104, 112, 120, 128, 136, 144, 153, 161
    };
    uint8_t secondary_chan;
    int i;

    if ((primary_chan >= 1 && primary_chan <= 9) ||
        (primary_chan >= 36 && primary_chan <= 157))
        secondary_chan = primary_chan + 4;
    else
        return 0;

    for (i = 0; i < nitems(valid_secondary_chan); i++) {
        if (secondary_chan == valid_secondary_chan[i])
            return 1;
    }

    return 0;
}

int
ieee80211_40mhz_valid_secondary_below(uint8_t primary_chan)
{
    static const uint8_t valid_secondary_chan[] = {
        1, 2, 3, 4, 5, 6, 7, 8, 9,
        36, 44, 52, 60, 100, 108, 116, 124, 132, 140, 149, 157
    };
    int8_t secondary_chan;
    int i;

    if ((primary_chan >= 5 && primary_chan <= 13) ||
        (primary_chan >= 40 && primary_chan <= 161))
        secondary_chan = primary_chan - 4;
    else
        return 0;

    for (i = 0; i < nitems(valid_secondary_chan); i++) {
        if (secondary_chan == valid_secondary_chan[i])
            return 1;
    }

    return 0;
}

/*
 * Only accept 40 MHz channel configurations that conform to
 * regulatory operating classes as defined by the 802.11ac spec.
 * Passing other configurations down to firmware can result in
 * regulatory assertions being trigged, such as fatal firmware
 * error 14FD in iwm(4).
 *
 * See 802.11ac 2013, page 380, Tables E-1 to E-5.
 */
int
ieee80211_40mhz_center_freq_valid(uint8_t primary_chan, uint8_t htop0)
{
    uint8_t sco;

    sco = ((htop0 & IEEE80211_HTOP0_SCO_MASK) >> IEEE80211_HTOP0_SCO_SHIFT);
    switch (sco) {
    case IEEE80211_HTOP0_SCO_SCN:
        return 1;
    case IEEE80211_HTOP0_SCO_SCA:
        return ieee80211_40mhz_valid_secondary_above(primary_chan);
    case IEEE80211_HTOP0_SCO_SCB:
        return ieee80211_40mhz_valid_secondary_below(primary_chan);
    }

    return 0;
}

/*
 * Install received HT op information in the node's state block.
 */
int
ieee80211_setup_htop(struct ieee80211_node *ni, const uint8_t *data,
    uint8_t len, int isprobe)
{
    if (len != 22)
        return 0;

    ni->ni_primary_chan = data[0]; /* corresponds to ni_chan */
    ni->ni_htop0 = data[1];
    if (!ieee80211_40mhz_center_freq_valid(data[0], data[1]))
        ni->ni_htop0 &= ~IEEE80211_HTOP0_SCO_MASK;
    ni->ni_htop1 = (data[2] | (data[3] << 8));
    ni->ni_htop2 = (data[3] | (data[4] << 8));

    /*
     * According to 802.11-2012 Table 8-130 the Basic MCS set is
     * only "present in Beacon, Probe Response, Mesh Peering Open
     * and Mesh Peering Confirm frames. Otherwise reserved."
     */
    if (isprobe)
        memcpy(ni->ni_basic_mcs, &data[6], sizeof(ni->ni_basic_mcs));

    return 1;
}

/*
 * Install received VHT caps information in the node's state block.
 */
void
ieee80211_setup_vhtcaps(struct ieee80211_node *ni, const uint8_t *data,
    uint8_t len)
{
    if (len != 12)
        return;

    ni->ni_vhtcaps = (data[0] | (data[1] << 8) | data[2] << 16 |
        data[3] << 24);
    ni->ni_vht_rxmcs = (data[4] | (data[5] << 8));
    ni->ni_vht_rx_max_lgi_mbit_s = ((data[6] | (data[7] << 8)) &
        IEEE80211_VHT_MAX_LGI_MBIT_S_MASK);
    ni->ni_vht_txmcs = (data[8] | (data[9] << 8));
    ni->ni_vht_tx_max_lgi_mbit_s = ((data[10] | (data[11] << 8)) &
        IEEE80211_VHT_MAX_LGI_MBIT_S_MASK);

    ni->ni_flags |= IEEE80211_NODE_VHTCAP;
}

/*
 * Only accept 80 MHz channel configurations that conform to
 * regulatory operating classes as defined by the 802.11ac spec.
 * Passing other configurations down to firmware can result in
 * regulatory assertions being trigged, such as fatal firmware
 * error 14FD in iwm(4).
 *
 * See 802.11ac 2013, page 380, Tables E-1 to E-5.
 */
int
ieee80211_80mhz_center_freq_valid(const uint8_t chanidx)
{
    static const uint8_t valid_center_chanidx[] = {
        42, 50, 58, 106, 112, 114, 138, 155
    };
    int i;

    for (i = 0; i < nitems(valid_center_chanidx); i++) {
        if (chanidx == valid_center_chanidx[i])
            return 1;
    }

    return 0;
}

/*
 * Install received VHT op information in the node's state block.
 */
int
ieee80211_setup_vhtop(struct ieee80211_node *ni, const uint8_t *data,
    uint8_t len, int isprobe)
{
    uint8_t sco;
    int have_40mhz;

    if (len != 5)
        return 0;

    if (data[0] != IEEE80211_VHTOP0_CHAN_WIDTH_HT &&
        data[0] != IEEE80211_VHTOP0_CHAN_WIDTH_80 &&
        data[0] != IEEE80211_VHTOP0_CHAN_WIDTH_160 &&
        data[0] != IEEE80211_VHTOP0_CHAN_WIDTH_8080)
        return 0;

    sco = ((ni->ni_htop0 & IEEE80211_HTOP0_SCO_MASK) >>
        IEEE80211_HTOP0_SCO_SHIFT);
    have_40mhz = (sco == IEEE80211_HTOP0_SCO_SCA ||
        sco == IEEE80211_HTOP0_SCO_SCB);

    if (have_40mhz && ieee80211_80mhz_center_freq_valid(data[1])) {
        ni->ni_vht_chan_width = data[0];
        ni->ni_vht_chan_center_freq_idx0 = data[1];

        /* Only used in non-consecutive 80-80 160MHz configs. */
        if (data[2] && ieee80211_80mhz_center_freq_valid(data[2]))
            ni->ni_vht_chan_center_freq_idx1 = data[2];
        else
            ni->ni_vht_chan_center_freq_idx1 = 0;
    } else {
        ni->ni_vht_chan_width = IEEE80211_VHTOP0_CHAN_WIDTH_HT;
        ni->ni_vht_chan_center_freq_idx0 = 0;
        ni->ni_vht_chan_center_freq_idx1 = 0;
    }

    ni->ni_vht_basic_mcs = (data[3] | data[4] << 8);
    return 1;
}

#ifndef IEEE80211_STA_ONLY
/*
 * Handle nodes switching from 11ac into legacy modes.
 */
void
ieee80211_clear_vhtcaps(struct ieee80211_node *ni)
{
    ni->ni_vhtcaps = 0;
    ni->ni_vht_rxmcs = 0;
    ni->ni_vht_rx_max_lgi_mbit_s = 0;
    ni->ni_vht_txmcs = 0;
    ni->ni_vht_tx_max_lgi_mbit_s = 0;

    ni->ni_flags &= ~(IEEE80211_NODE_VHT | IEEE80211_NODE_VHT_SGI80 |
        IEEE80211_NODE_VHT_SGI160 | IEEE80211_NODE_VHTCAP);

}
#endif

/*
 * Install received rate set information in the node's state block.
 */
int
ieee80211_setup_rates(struct ieee80211com *ic, struct ieee80211_node *ni,
    const u_int8_t *rates, const u_int8_t *xrates, int flags)
{
    struct ieee80211_rateset *rs = &ni->ni_rates;

    memset(rs, 0, sizeof(*rs));
    rs->rs_nrates = rates[1];
    memcpy(rs->rs_rates, rates + 2, rs->rs_nrates);
    if (xrates != NULL) {
        u_int8_t nxrates;
        /*
         * Tack on 11g extended supported rate element.
         */
        nxrates = xrates[1];
        if (rs->rs_nrates + nxrates > IEEE80211_RATE_MAXSIZE) {
            nxrates = IEEE80211_RATE_MAXSIZE - rs->rs_nrates;
            DPRINTF(("extended rate set too large; "
                "only using %u of %u rates\n",
                nxrates, xrates[1]));
            ic->ic_stats.is_rx_rstoobig++;
        }
        memcpy(rs->rs_rates + rs->rs_nrates, xrates+2, nxrates);
        rs->rs_nrates += nxrates;
    }
    return ieee80211_fix_rate(ic, ni, flags);
}

void
ieee80211_node_trigger_addba_req(struct ieee80211_node *ni, int tid)
{
    if (ni->ni_tx_ba[tid].ba_state == IEEE80211_BA_INIT &&
        !timeout_pending(&ni->ni_addba_req_to[tid])) {
        timeout_add_sec(&ni->ni_addba_req_to[tid],
            ni->ni_addba_req_intval[tid]);
    }
}

void
ieee80211_node_addba_request(struct ieee80211_node *ni, int tid)
{
    struct ieee80211com *ic = ni->ni_ic;
    uint16_t ssn = ni->ni_qos_txseqs[tid];

    ieee80211_addba_request(ic, ni, ssn, tid);
}

void
ieee80211_node_addba_request_ac_be_to(void *arg)
{
    struct ieee80211_node *ni = (typeof ni)arg;
    ieee80211_node_addba_request(ni, EDCA_AC_BE);
}

void
ieee80211_node_addba_request_ac_bk_to(void *arg)
{
    struct ieee80211_node *ni = (typeof ni)arg;
    ieee80211_node_addba_request(ni, EDCA_AC_BK);
}

void
ieee80211_node_addba_request_ac_vi_to(void *arg)
{
    struct ieee80211_node *ni = (typeof ni)arg;
    ieee80211_node_addba_request(ni, EDCA_AC_VI);
}

void
ieee80211_node_addba_request_ac_vo_to(void *arg)
{
    struct ieee80211_node *ni = (typeof ni)arg;
    ieee80211_node_addba_request(ni, EDCA_AC_VO);
}

#ifndef IEEE80211_STA_ONLY
/*
 * Check if the specified node supports ERP.
 */
int
ieee80211_iserp_sta(const struct ieee80211_node *ni)
{
    static const u_int8_t rates[] = { 2, 4, 11, 22, 12, 24, 48 };
    const struct ieee80211_rateset *rs = &ni->ni_rates;
    int i, j;

    /*
     * A STA supports ERP operation if it includes all the Clause 19
     * mandatory rates in its supported rate set.
     */
    for (i = 0; i < nitems(rates); i++) {
        for (j = 0; j < rs->rs_nrates; j++) {
            if ((rs->rs_rates[j] & IEEE80211_RATE_VAL) == rates[i])
                break;
        }
        if (j == rs->rs_nrates)
            return 0;
    }
    return 1;
}

/*
 * This function is called to notify the 802.1X PACP machine that a new
 * 802.1X port is enabled and must be authenticated. For 802.11, a port
 * becomes enabled whenever a STA successfully completes Open System
 * authentication with an AP.
 */
void
ieee80211_needs_auth(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    /*
     * XXX this could be done via the route socket of via a dedicated
     * EAP socket or another kernel->userland notification mechanism.
     * The notification should include the MAC address (ni_macaddr).
     */
}

/*
 * Handle an HT STA joining an HT network.
 */
void
ieee80211_node_join_ht(struct ieee80211com *ic, struct ieee80211_node *ni)
{
//    enum ieee80211_htprot;

    /* Update HT protection setting. */
    if ((ni->ni_flags & IEEE80211_NODE_HT) == 0) {
        uint16_t htop1 = ic->ic_bss->ni_htop1;
        htop1 &= ~IEEE80211_HTOP1_PROT_MASK;
        htop1 |= IEEE80211_HTPROT_NONHT_MIXED;
        ic->ic_bss->ni_htop1 = htop1;
        if (ic->ic_updateprot)
            ic->ic_updateprot(ic);
    }
}

/*
 * Handle a station joining an RSN network.
 */
void
ieee80211_node_join_rsn(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    DPRINTF(("station %s associated using proto %d akm 0x%x "
        "cipher 0x%x groupcipher 0x%x\n", ether_sprintf(ni->ni_macaddr),
        ni->ni_rsnprotos, ni->ni_rsnakms, ni->ni_rsnciphers,
        ni->ni_rsngroupcipher));

    ni->ni_rsn_state = RSNA_AUTHENTICATION;

    ni->ni_key_count = 0;
    ni->ni_port_valid = 0;
    ni->ni_flags &= ~IEEE80211_NODE_TXRXPROT;
    ni->ni_flags &= ~IEEE80211_NODE_RSN_NEW_PTK;
    ni->ni_replaycnt = -1;    /* XXX */
    ni->ni_rsn_retries = 0;
    ni->ni_rsncipher = (typeof ni->ni_rsncipher)ni->ni_rsnciphers;

    ni->ni_rsn_state = RSNA_AUTHENTICATION_2;

    /* generate a new authenticator nonce (ANonce) */
    arc4random_buf(ni->ni_nonce, EAPOL_KEY_NONCE_LEN);

    if (!ieee80211_is_8021x_akm((enum ieee80211_akm)ni->ni_rsnakms)) {
        memcpy(ni->ni_pmk, ic->ic_psk, IEEE80211_PMK_LEN);
        ni->ni_flags |= IEEE80211_NODE_PMK;
        (void)ieee80211_send_4way_msg1(ic, ni);
    } else if (ni->ni_flags & IEEE80211_NODE_PMK) {
        /* skip 802.1X auth if a cached PMK was found */
        (void)ieee80211_send_4way_msg1(ic, ni);
    } else {
        /* no cached PMK found, needs full 802.1X auth */
        ieee80211_needs_auth(ic, ni);
    }
}

void
ieee80211_count_longslotsta(void *arg, struct ieee80211_node *ni)
{
    int *longslotsta = (typeof longslotsta)arg;

    if (ni->ni_associd == 0 || ni->ni_state == IEEE80211_STA_COLLECT)
        return;

    if (!(ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME))
        (*longslotsta)++;
}

void
ieee80211_count_nonerpsta(void *arg, struct ieee80211_node *ni)
{
    int *nonerpsta = (typeof nonerpsta)arg;

    if (ni->ni_associd == 0 || ni->ni_state == IEEE80211_STA_COLLECT)
        return;

    if (!ieee80211_iserp_sta(ni))
        (*nonerpsta)++;
}

void
ieee80211_count_pssta(void *arg, struct ieee80211_node *ni)
{
    int *pssta = (typeof pssta)arg;

    if (ni->ni_associd == 0 || ni->ni_state == IEEE80211_STA_COLLECT)
        return;

    if (ni->ni_pwrsave == IEEE80211_PS_DOZE)
        (*pssta)++;
}

void
ieee80211_count_rekeysta(void *arg, struct ieee80211_node *ni)
{
    int *rekeysta = (typeof rekeysta)arg;

    if (ni->ni_associd == 0 || ni->ni_state == IEEE80211_STA_COLLECT)
        return;

    if (ni->ni_flags & IEEE80211_NODE_REKEY)
        (*rekeysta)++;
}

/*
 * Handle a station joining an 11g network.
 */
void
ieee80211_node_join_11g(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    int longslotsta = 0, nonerpsta = 0;

    if (!(ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME)) {
        /*
         * Joining STA doesn't support short slot time.  We must
         * disable the use of short slot time for all other associated
         * STAs and give the driver a chance to reconfigure the
         * hardware.
         */
        ieee80211_iterate_nodes(ic,
            ieee80211_count_longslotsta, &longslotsta);
        if (longslotsta == 1) {
            if (ic->ic_caps & IEEE80211_C_SHSLOT)
                ieee80211_set_shortslottime(ic, 0);
        }
        DPRINTF(("[%s] station needs long slot time, count %d\n",
            ether_sprintf(ni->ni_macaddr), longslotsta));
    }

    if (!ieee80211_iserp_sta(ni)) {
        /*
         * Joining STA is non-ERP.
         */
        ieee80211_iterate_nodes(ic,
            ieee80211_count_nonerpsta, &nonerpsta);
        DPRINTF(("[%s] station is non-ERP, %d non-ERP "
            "stations associated\n", ether_sprintf(ni->ni_macaddr),
            nonerpsta));
        /* must enable the use of protection */
        if (ic->ic_protmode != IEEE80211_PROT_NONE) {
            DPRINTF(("enable use of protection\n"));
            ic->ic_flags |= IEEE80211_F_USEPROT;
        }

        if (!(ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE))
            ic->ic_flags &= ~IEEE80211_F_SHPREAMBLE;
    } else
        ni->ni_flags |= IEEE80211_NODE_ERP;
}

void
ieee80211_node_join(struct ieee80211com *ic, struct ieee80211_node *ni,
    int resp)
{
    int newassoc = (ni->ni_state != IEEE80211_STA_ASSOC);

    if (ni->ni_associd == 0) {
        u_int16_t aid;

        /*
         * It would be clever to search the bitmap
         * more efficiently, but this will do for now.
         */
        for (aid = 1; aid < ic->ic_max_aid; aid++) {
            if (!IEEE80211_AID_ISSET(aid,
                ic->ic_aid_bitmap))
                break;
        }
        if (aid >= ic->ic_max_aid) {
            IEEE80211_SEND_MGMT(ic, ni, resp,
                IEEE80211_REASON_ASSOC_TOOMANY);
            ieee80211_node_leave(ic, ni);
            return;
        }
        ni->ni_associd = aid | 0xc000;
        IEEE80211_AID_SET(ni->ni_associd, ic->ic_aid_bitmap);
        if (ic->ic_curmode == IEEE80211_MODE_11G ||
            (ic->ic_curmode == IEEE80211_MODE_11N &&
            IEEE80211_IS_CHAN_2GHZ(ic->ic_bss->ni_chan)))
            ieee80211_node_join_11g(ic, ni);
    }

    DPRINTF(("station %s %s associated at aid %d\n",
        ether_sprintf(ni->ni_macaddr), newassoc ? "newly" : "already",
        ni->ni_associd & ~0xc000));

    ieee80211_ht_negotiate(ic, ni);
    if (ic->ic_flags & IEEE80211_F_HTON)
        ieee80211_node_join_ht(ic, ni);

    /* give driver a chance to setup state like ni_txrate */
    if (ic->ic_newassoc)
        (*ic->ic_newassoc)(ic, ni, newassoc);
    IEEE80211_SEND_MGMT(ic, ni, resp, IEEE80211_STATUS_SUCCESS);
    ieee80211_node_newstate(ni, IEEE80211_STA_ASSOC);

    if (!(ic->ic_flags & IEEE80211_F_RSNON)) {
        ni->ni_port_valid = 1;
        ni->ni_rsncipher = IEEE80211_CIPHER_USEGROUP;
    } else
        ieee80211_node_join_rsn(ic, ni);

#if NBRIDGE > 0
    /*
     * If the parent interface is a bridge port, learn
     * the node's address dynamically on this interface.
     */
    if (ic->ic_if.if_bridgeidx != 0)
        bridge_update(&ic->ic_if,
            (struct ether_addr *)ni->ni_macaddr, 0);
#endif
}

/*
 * Handle an HT STA leaving an HT network.
 */
void
ieee80211_node_leave_ht(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    struct ieee80211_rx_ba *ba;
    u_int8_t tid;
    int i;

    /* free all Block Ack records */
    ieee80211_ba_del(ni);
    for (tid = 0; tid < IEEE80211_NUM_TID; tid++) {
        ba = &ni->ni_rx_ba[tid];
        if (ba->ba_buf != NULL) {
            for (i = 0; i < IEEE80211_BA_MAX_WINSZ; i++)
                m_freem(ba->ba_buf[i].m);
            free(ba->ba_buf, M_DEVBUF,
                IEEE80211_BA_MAX_WINSZ * sizeof(*ba->ba_buf));
            ba->ba_buf = NULL;
        }
    }

    ieee80211_clear_htcaps(ni);
}

/*
 * Handle a VHT STA leaving a VHT network.
 */
void
ieee80211_node_leave_vht(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    ieee80211_clear_vhtcaps(ni);
}

/*
 * Handle a station leaving an RSN network.
 */
void
ieee80211_node_leave_rsn(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    int rekeysta = 0;

    ni->ni_rsn_state = RSNA_INITIALIZE;
    if (ni->ni_flags & IEEE80211_NODE_REKEY) {
        ni->ni_flags &= ~IEEE80211_NODE_REKEY;
        ieee80211_iterate_nodes(ic,
            ieee80211_count_rekeysta, &rekeysta);
        if (rekeysta == 0)
            ieee80211_setkeysdone(ic);
    }
    ni->ni_flags &= ~IEEE80211_NODE_PMK;
    ni->ni_rsn_gstate = RSNA_IDLE;

    timeout_del(&ni->ni_eapol_to);
    timeout_del(&ni->ni_sa_query_to);

    ni->ni_rsn_retries = 0;
    ni->ni_flags &= ~IEEE80211_NODE_TXRXPROT;
    ni->ni_port_valid = 0;
    (*ic->ic_delete_key)(ic, ni, &ni->ni_pairwise_key);
}

/*
 * Handle a station leaving an 11g network.
 */
void
ieee80211_node_leave_11g(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    int longslotsta = 0, nonerpsta = 0;

    if (!(ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME)) {
        /* leaving STA did not support short slot time */
        ieee80211_iterate_nodes(ic,
            ieee80211_count_longslotsta, &longslotsta);
        if (longslotsta == 1) {
            /*
             * All associated STAs now support short slot time, so
             * enable this feature and give the driver a chance to
             * reconfigure the hardware. Notice that IBSS always
             * use a long slot time.
             */
            if ((ic->ic_caps & IEEE80211_C_SHSLOT) &&
                ic->ic_opmode != IEEE80211_M_IBSS)
                ieee80211_set_shortslottime(ic, 1);
        }
        DPRINTF(("[%s] long slot time station leaves, count %d\n",
            ether_sprintf(ni->ni_macaddr), longslotsta));
    }

    if (!(ni->ni_flags & IEEE80211_NODE_ERP)) {
        /* leaving STA was non-ERP */
        ieee80211_iterate_nodes(ic,
            ieee80211_count_nonerpsta, &nonerpsta);
        if (nonerpsta == 1) {
            /*
             * All associated STAs are now ERP capable, disable use
             * of protection and re-enable short preamble support.
             */
            ic->ic_flags &= ~IEEE80211_F_USEPROT;
            if (ic->ic_caps & IEEE80211_C_SHPREAMBLE)
                ic->ic_flags |= IEEE80211_F_SHPREAMBLE;
        }
        DPRINTF(("[%s] non-ERP station leaves, count %d\n",
            ether_sprintf(ni->ni_macaddr), nonerpsta));
    }
}

void
ieee80211_node_leave_pwrsave(struct ieee80211com *ic,
    struct ieee80211_node *ni)
{
//    struct mbuf_queue keep = MBUF_QUEUE_INITIALIZER(IFQ_MAXLEN, IPL_NET);
    struct mbuf_queue keep;
    mq_init(&keep, IFQ_MAXLEN, IPL_NET);
    mbuf_t m;

    if (ni->ni_pwrsave == IEEE80211_PS_DOZE)
        ni->ni_pwrsave = IEEE80211_PS_AWAKE;

    if (mq_len(&ni->ni_savedq) > 0) {
        if (ic->ic_set_tim != NULL)
            (*ic->ic_set_tim)(ic, ni->ni_associd, 0);
    }
    while ((m = mq_dequeue(&ni->ni_savedq)) != NULL) {
        if (ni->ni_refcnt > 0)
            ieee80211_node_decref(ni);
        m_freem(m);
    }

    /* Purge frames queued for transmission during DTIM. */
    while ((m = mq_dequeue(&ic->ic_pwrsaveq)) != NULL) {
        if ((typeof ni)mbuf_pkthdr_rcvif(m) == ni) {
            if (ni->ni_refcnt > 0)
                ieee80211_node_decref(ni);
            m_freem(m);
        } else
            mq_enqueue(&keep, m);
    }
    while ((m = mq_dequeue(&keep)) != NULL)
        mq_enqueue(&ic->ic_pwrsaveq, m);
}

/*
 * Handle bookkeeping for station deauthentication/disassociation
 * when operating as an ap.
 */
void
ieee80211_node_leave(struct ieee80211com *ic, struct ieee80211_node *ni)
{
    if (ic->ic_opmode != IEEE80211_M_HOSTAP)
        panic("not in ap mode, mode %u", ic->ic_opmode);

    if (ni->ni_state == IEEE80211_STA_COLLECT)
        return;
    /*
     * If node wasn't previously associated all we need to do is
     * reclaim the reference.
     */
    if (ni->ni_associd == 0) {
        ieee80211_node_newstate(ni, IEEE80211_STA_COLLECT);
        return;
    }

    ieee80211_node_leave_pwrsave(ic, ni);

    if (ic->ic_flags & IEEE80211_F_RSNON)
        ieee80211_node_leave_rsn(ic, ni);

    if (ic->ic_curmode == IEEE80211_MODE_11G ||
        (ic->ic_curmode == IEEE80211_MODE_11N &&
        IEEE80211_IS_CHAN_2GHZ(ic->ic_bss->ni_chan)))
        ieee80211_node_leave_11g(ic, ni);

    if (ni->ni_flags & IEEE80211_NODE_HT)
        ieee80211_node_leave_ht(ic, ni);
    if (ni->ni_flags & IEEE80211_NODE_VHT)
        ieee80211_node_leave_vht(ic, ni);

    if (ic->ic_node_leave != NULL)
        (*ic->ic_node_leave)(ic, ni);

    ieee80211_node_newstate(ni, IEEE80211_STA_COLLECT);

#if NBRIDGE > 0
    /*
     * If the parent interface is a bridge port, delete
     * any dynamically learned address for this node.
     */
    if (ic->ic_if.if_bridgeidx != 0)
        bridge_update(&ic->ic_if,
            (struct ether_addr *)ni->ni_macaddr, 1);
#endif
}

static int
ieee80211_do_slow_print(struct ieee80211com *ic, int *did_print)
{
    static const struct timeval merge_print_intvl = {
        .tv_sec = 1, .tv_usec = 0
    };
    if ((ic->ic_if.if_flags & IFF_LINK0) == 0)
        return 0;
    if (!*did_print && (ic->ic_if.if_flags & IFF_DEBUG) == 0 &&
        !ratecheck(&ic->ic_last_merge_print, &merge_print_intvl))
        return 0;

    *did_print = 1;
    return 1;
}

/* ieee80211_ibss_merge helps merge 802.11 ad hoc networks.  The
 * convention, set by the Wireless Ethernet Compatibility Alliance
 * (WECA), is that an 802.11 station will change its BSSID to match
 * the "oldest" 802.11 ad hoc network, on the same channel, that
 * has the station's desired SSID.  The "oldest" 802.11 network
 * sends beacons with the greatest TSF timestamp.
 *
 * Return ENETRESET if the BSSID changed, 0 otherwise.
 *
 * XXX Perhaps we should compensate for the time that elapses
 * between the MAC receiving the beacon and the host processing it
 * in ieee80211_ibss_merge.
 */
int
ieee80211_ibss_merge(struct ieee80211com *ic, struct ieee80211_node *ni,
    u_int64_t local_tsft)
{
    u_int64_t beacon_tsft;
    int did_print = 0, sign;
    union {
        u_int64_t    word;
        u_int8_t    tstamp[8];
    } u;

    /* ensure alignment */
    (void)memcpy(&u, &ni->ni_tstamp[0], sizeof(u));
    beacon_tsft = letoh64(u.word);

    /* we are faster, let the other guy catch up */
    if (beacon_tsft < local_tsft)
        sign = -1;
    else
        sign = 1;

    if (IEEE80211_ADDR_EQ(ni->ni_bssid, ic->ic_bss->ni_bssid)) {
        if (!ieee80211_do_slow_print(ic, &did_print))
            return 0;
        printf("%s: tsft offset %s%llu\n", ic->ic_if.if_xname,
            (sign < 0) ? "-" : "",
            (sign < 0)
            ? (local_tsft - beacon_tsft)
            : (beacon_tsft - local_tsft));
        return 0;
    }

    if (sign < 0)
        return 0;

    if (ieee80211_match_bss(ic, ni, 0) != 0)
        return 0;

    if (ieee80211_do_slow_print(ic, &did_print)) {
        printf("%s: ieee80211_ibss_merge: bssid mismatch %s\n",
            ic->ic_if.if_xname, ether_sprintf(ni->ni_bssid));
        printf("%s: my tsft %llu beacon tsft %llu\n",
            ic->ic_if.if_xname, local_tsft, beacon_tsft);
        printf("%s: sync TSF with %s\n",
            ic->ic_if.if_xname, ether_sprintf(ni->ni_macaddr));
    }

    ic->ic_flags &= ~IEEE80211_F_SIBSS;

    /* negotiate rates with new IBSS */
    ieee80211_fix_rate(ic, ni, IEEE80211_F_DOFRATE |
        IEEE80211_F_DONEGO | IEEE80211_F_DODEL);
    if (ni->ni_rates.rs_nrates == 0) {
        if (ieee80211_do_slow_print(ic, &did_print)) {
            printf("%s: rates mismatch, BSSID %s\n",
                ic->ic_if.if_xname, ether_sprintf(ni->ni_bssid));
        }
        return 0;
    }

    if (ieee80211_do_slow_print(ic, &did_print)) {
        printf("%s: sync BSSID %s -> ",
            ic->ic_if.if_xname, ether_sprintf(ic->ic_bss->ni_bssid));
        printf("%s ", ether_sprintf(ni->ni_bssid));
        printf("(from %s)\n", ether_sprintf(ni->ni_macaddr));
    }

    ieee80211_node_newstate(ni, IEEE80211_STA_BSS);
    (*ic->ic_node_copy)(ic, ic->ic_bss, ni);

    return ENETRESET;
}

void
ieee80211_set_tim(struct ieee80211com *ic, int aid, int set)
{
    if (set)
        setbit(ic->ic_tim_bitmap, aid & ~0xc000);
    else
        clrbit(ic->ic_tim_bitmap, aid & ~0xc000);
}

/*
 * This function shall be called by drivers immediately after every DTIM.
 * Transmit all group addressed MSDUs buffered at the AP.
 */
void
ieee80211_notify_dtim(struct ieee80211com *ic)
{
    /* NB: group addressed MSDUs are buffered in ic_bss */
    struct ieee80211_node *ni = ic->ic_bss;
    struct ifnet *ifp = &ic->ic_if;
    struct ieee80211_frame *wh;
    mbuf_t m;

    KASSERT(ic->ic_opmode == IEEE80211_M_HOSTAP);

    while ((m = mq_dequeue(&ni->ni_savedq)) != NULL) {
        if (!mq_empty(&ni->ni_savedq)) {
            /* more queued frames, set the more data bit */
            wh = mtod(m, struct ieee80211_frame *);
            wh->i_fc[1] |= IEEE80211_FC1_MORE_DATA;
        }
        mq_enqueue(&ic->ic_pwrsaveq, m);
        if_start(ifp);
    }
    /* XXX assumes everything has been sent */
    ic->ic_tim_mcast_pending = 0;
}
#endif    /* IEEE80211_STA_ONLY */

/*
 * Compare nodes in the tree by lladdr
 */
int
ieee80211_node_cmp(const struct ieee80211_node *b1,
    const struct ieee80211_node *b2)
{
    return (memcmp(b1->ni_macaddr, b2->ni_macaddr, IEEE80211_ADDR_LEN));
}

/*
 * Compare nodes in the tree by essid
 */
int
ieee80211_ess_cmp(const struct ieee80211_ess_rbt *b1,
    const struct ieee80211_ess_rbt *b2)
{
    return (memcmp(b1->essid, b2->essid, IEEE80211_NWID_LEN));
}

/*
 * Generate red-black tree function logic
 */
RBT_GENERATE(ieee80211_tree, ieee80211_node, ni_node, ieee80211_node_cmp);
RBT_GENERATE(ieee80211_ess_tree, ieee80211_ess_rbt, ess_rbt, ieee80211_ess_cmp);
